U.S President Donald Trump looks on during a meeting with President Petro Poroshenko of Ukraine in the Oval Office of the White House in Washington, DC, USA, on June 20, 2017. Photo by Olivier Douliery/ABACAPRESS.COM

U.S President Donald Trump speaks during a meeting with President Petro Poroshenko of Ukraine in the Oval Office of the White House in Washington, DC, USA, on June 20, 2017. Photo by Olivier Douliery/ABACAPRESS.COM

U.S President Donald Trump speaks during a meeting with President Petro Poroshenko of Ukraine in the Oval Office of the White House in Washington, DC, USA, on June 20, 2017. Photo by Olivier Douliery/ABACAPRESS.COM

U.S President Donald Trump looks on during a meeting with President Petro Poroshenko of Ukraine in the Oval Office of the White House in Washington, DC, USA, on June 20, 2017. Photo by Olivier Douliery/ABACAPRESS.COM

U.S President Donald Trump looks on during a meeting with President Petro Poroshenko of Ukraine in the Oval Office of the White House in Washington, DC, USA, on June 20, 2017. Photo by Olivier Douliery/ABACAPRESS.COM

U.S President Donald Trump meets with President Petro Poroshenko of Ukraine in the Oval Office of the White House in Washington, DC, USA, on June 20, 2017. Photo by Olivier Douliery/ABACAPRESS.COM

U.S President Donald Trump speaks during a meeting with President Petro Poroshenko of Ukraine in the Oval Office of the White House in Washington, DC, USA, on June 20, 2017. Photo by Olivier Douliery/ABACAPRESS.COM

U.S President Donald Trump meets with President Petro Poroshenko of Ukraine as National Security Advisor H.R. McMaster (R) and Vice President Mike Pence look on in the Oval Office of the White House in Washington, DC, USA, on June 20, 2017. Photo by Olivier Douliery/ABACAPRESS.COM

U.S President Donald Trump meets with President Petro Poroshenko of Ukraine as National Security Advisor H.R. McMaster (R) and Vice President Mike Pence look on in the Oval Office of the White House in Washington, DC, USA, on June 20, 2017. Photo by Olivier Douliery/ABACAPRESS.COM

President Petro Poroshenko of Ukrainelooks on during a meeting with U.S President Donald Trump in the Oval Office of the White House in Washington, DC, USA, on June 20, 2017. Photo by Olivier Douliery/ABACAPRESS.COM

U.S President Donald Trump checks hands with President Petro Poroshenko of Ukraine in the Oval Office of the White House in Washington, DC, USA, on June 20, 2017. Photo by Olivier Douliery/ABACAPRESS.COM

U.S President Donald Trump meets with President Petro Poroshenko of Ukraine in the Oval Office of the White House in Washington, DC, USA, on June 20, 2017. Photo by Olivier Douliery/ABACAPRESS.COM

U.S President Donald Trump meets with President Petro Poroshenko of Ukraine in the Oval Office of the White House in Washington, DC, USA, on June 20, 2017. Photo by Olivier Douliery/ABACAPRESS.COM

President Donald Trump speaks during a meeting with Ukrainian President Petro Poroshenko in the Oval Office of the White House, Tuesday, June 20, 2017, in Washington. (AP Photo/Evan Vucci)

President Donald Trump speaks during a meeting with Ukrainian President Petro Poroshenko in the Oval Office of the White House, Tuesday, June 20, 2017, in Washington. (AP Photo/Evan Vucci)

President Donald Trump listens as Ukrainian President Petro Poroshenko speaks during a meeting in the Oval Office of the White House, Tuesday, June 20, 2017, in Washington. From left, Poroshenko, Trump, Vice President Mike Pence, and National Security Adviser H.R. McMaster. (AP Photo/Evan Vucci)

President Donald Trump listens during a meeting with Ukrainian President Petro Poroshenko in the Oval Office of the White House, Tuesday, June 20, 2017, in Washington. From left, Trump, Vice President Mike Pence, and National Security Adviser H.R. McMaster. (AP Photo/Evan Vucci)

President Donald Trump shakes hands with Ukrainian President Petro Poroshenko during a meeting in the Oval Office of the White House, Tuesday, June 20, 2017, in Washington. From left, Poroshenko, Trump, Vice President Mike Pence, and National Security Adviser H.R. McMaster. (AP Photo/Evan Vucci)

President Donald Trump speaks during a meeting with Ukrainian President Petro Poroshenko in the Oval Office of the White House, Tuesday, June 20, 2017, in Washington. (AP Photo/Evan Vucci)

President Donald Trump listens during a meeting with Ukrainian President Petro Poroshenko in the Oval Office of the White House, Tuesday, June 20, 2017, in Washington. (AP Photo/Evan Vucci)

President Donald Trump speaks during a meeting with Ukrainian President Petro Poroshenko in the Oval Office of the White House, Tuesday, June 20, 2017, in Washington. (AP Photo/Evan Vucci)

President Donald Trump shakes hands with Ukrainian President Petro Poroshenko during a meeting in the Oval Office of the White House, Tuesday, June 20, 2017, in Washington. (AP Photo/Evan Vucci)

President Donald Trump listens during a meeting with Ukrainian President Petro Poroshenko in the Oval Office of the White House, Tuesday, June 20, 2017, in Washington. (AP Photo/Evan Vucci)

President Donald Trump speaks during a meeting with Ukrainian President Petro Poroshenko in the Oval Office of the White House, Tuesday, June 20, 2017, in Washington. (AP Photo/Evan Vucci)

President Donald Trump meets with Ukrainian President Petro Poroshenko in the Oval Office of the White House, Tuesday, June 20, 2017, in Washington. (AP Photo/Evan Vucci)

Defense Secretary Jim Mattis hosts welcomes Ukraine President Petro Poroshenko at the Pentagon, Tuesday, June 20, 2017, in Arlington. (AP Photo/Andrew Harnik)

Defense Secretary Jim Mattis, left, greets Ukrainian President Petro Poroshenko, right, during a ceremony at the Pentagon, Tuesday, June 20, 2017, in Washington. (AP Photo/Andrew Harnik)

Defense Secretary Jim Mattis, greets Ukrainian President Petro Poroshenko at the Pentagon, Tuesday, June 20, 2017, in Washington. (AP Photo/Andrew Harnik)

Defense Secretary Jim Mattis, right, greets Ukrainian President Petro Poroshenko at the Pentagon, Tuesday, June 20, 2017, in Washington. (AP Photo/Andrew Harnik)

Defense Secretary Jim Mattis, left, and Ukrainian President Petro Poroshenko, right, participate in an arrival ceremony at the Pentagon, Tuesday, June 20, 2017, in Washington. (AP Photo/Andrew Harnik)

Defense Secretary Jim Mattis, left, and Ukrainian President Petro Poroshenko, second from left, participate in an arrival ceremony at the Pentagon, Tuesday, June 20, 2017, in Washington. (AP Photo/Andrew Harnik)

Ukrainian President Petro Poroshenko gives a thumbs up during a meeting with Defense Secretary Jim Mattis at the Pentagon, Tuesday, June 20, 2017, in Washington. (AP Photo/Andrew Harnik)

US President Donald Trump meets with his Ukrainian counterpart Petro Poroshenko in the Oval Office at the White House in Washington, DC, on June 20, 2017. / AFP PHOTO / NICHOLAS KAMM

US President Donald Trump meets with his Ukrainian counterpart Petro Poroshenko in the Oval Office at the White House in Washington, DC, on June 20, 2017. / AFP PHOTO / NICHOLAS KAMM

US President Donald Trump meets with his Ukrainian counterpart Petro Poroshenko in the Oval Office at the White House in Washington, DC, on June 20, 2017. / AFP PHOTO / NICHOLAS KAMM

US President Donald Trump meets with his Ukrainian counterpart Petro Poroshenko in the Oval Office at the White House in Washington, DC, on June 20, 2017. / AFP PHOTO / NICHOLAS KAMM

US President Donald Trump meets with his Ukrainian counterpart Petro Poroshenko as Vice President Mike Pence (2nd R) and National Security Adviser H.R. McMaster (R) look on in the Oval Office at the White House in Washington, DC, on June 20, 2017. / AFP PHOTO / NICHOLAS KAMM

US President Donald Trump meets with his Ukrainian counterpart Petro Poroshenko in the Oval Office at the White House in Washington, DC, on June 20, 2017. / AFP PHOTO / NICHOLAS KAMM

US President Donald Trump speaks to the press as he meets with his Ukrainian counterpart Petro Poroshenko(not seen) in the Oval Office at the White House in Washington, DC, on June 20, 2017. / AFP PHOTO / NICHOLAS KAMM

US President Donald Trump meets with his Ukrainian counterpart Petro Poroshenko in the Oval Office at the White House in Washington, DC, on June 20, 2017. / AFP PHOTO / NICHOLAS KAMM

US President Donald Trump meets with his Ukrainian counterpart Petro Poroshenko in the Oval Office at the White House in Washington, DC, on June 20, 2017. / AFP PHOTO / NICHOLAS KAMM

US President Donald Trump looks on as he meets with his Ukrainian counterpart Petro Poroshenko in the Oval Office at the White House in Washington, DC, on June 20, 2017. / AFP PHOTO / NICHOLAS KAMM

US President Donald Trump speaks to the press as Vice President Mike Pence looks on during a meeting with his Ukrainian counterpart Petro Poroshenko in the Oval Office at the White House in Washington, DC, on June 20, 2017. / AFP PHOTO / NICHOLAS KAMM

US President Donald Trump meets with his Ukrainian counterpart Petro Poroshenko in the Oval Office at the White House in Washington, DC, on June 20, 2017. / AFP PHOTO / NICHOLAS KAMM

Members of the military arrive before US Secretary of Defense James Mattis greets Ukraine's President Petro Poroshenko outside the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis waits to greet Ukraine's President Petro Poroshenko outside the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis waits to greet Ukraine's President Petro Poroshenko outside the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis (2L) greets Ukraine's President Petro Poroshenko outside the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis (front) and Ukraine's President Petro Poroshenko walk into the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis (2ndL) greets Ukraine's President Petro Poroshenko outside the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis (L) and Ukraine's President Petro Poroshenko walk to the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis (L) and Ukraine's President Petro Poroshenko listen to the Ukrainian national anthem outside the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis (L) and Ukraine's President Petro Poroshenko listen to the Ukrainian national anthem outside the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

Sailors wait for US Secretary of Defense James Mattis to greet Ukraine's President Petro Poroshenko outside the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis waits to greet Ukraine's President Petro Poroshenko outside the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis waits to greet Ukraine's President Petro Poroshenko outside the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis (L) and Ukraine's President Petro Poroshenko listen to the US national anthem outside the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

Ukraine's President Petro Poroshenko smiles at US Secretary of Defense James Mattis outside the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis(C) takes his seat for a meeting with Ukraine's President Petro Poroshenko at the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis speaks before a meeting with Ukraine's President Petro Poroshenko at the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis waits before a meeting with Ukraine's President Petro Poroshenko at the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of Defense James Mattis smiles before a meeting with Ukraine's President Petro Poroshenko at the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

Ukraine's President Petro Poroshenko speaks before a meeting with US Secretary of Defense James Mattis at the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

Ukraine's President Petro Poroshenko waits before a meeting with US Secretary of Defense James Mattis at the Pentagon on June 20, 2017 in Washington, DC. / AFP PHOTO / Brendan Smialowski

US Secretary of State Rex Tillerson shakes hands with Ukrainian President Petro Poroshenko at the US State Department in Washington, DC, June 20, 2017. / AFP PHOTO / JIM WATSON

US Secretary of State Rex Tillerson(R) meets with Ukrainian President Petro Poroshenko at the US State Department in Washington, DC, June 20, 2017. / AFP PHOTO / JIM WATSON

US Secretary of State Rex Tillerson (R) waves off a question from the press during a meeting with Ukrainian President Petro Poroshenko at the US State Department in Washington, DC, June 20, 2017. / AFP PHOTO / JIM WATSON

In this photo released by the International Monetary Fund, Managing Director Christine Lagarde (R) (R) greets Ukrainian President Petro Poroshenko (L) at the IMF Headquarters June 20, 2017 at the IMF Headquarters in Washington, DC. / AFP PHOTO / INTERNATIONAL MONETARY FUND / STEPHEN JAFFE / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / International Monetary Fund/ Stephen JAFFE- NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

In this photo released by the International Monetary Fund, Managing Director Christine Lagarde (R speaks with Ukrainian President Petro Poroshenko (L) at the IMF Headquarters June 20, 2017 at the IMF Headquarters in Washington, DC. / AFP PHOTO / INTERNATIONAL MONETARY FUND AND AFP PHOTO / STEPHEN JAFFE / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / International Monetary Fund/ Stephen JAFFE- NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

In this photo released by the International Monetary Fund, Managing Director Christine Lagarde (R speaks with Ukrainian President Petro Poroshenko (L) at the IMF Headquarters June 20, 2017 at the IMF Headquarters in Washington, DC. / AFP PHOTO / INTERNATIONAL MONETARY FUND AND AFP PHOTO / STEPHEN JAFFE / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / International Monetary Fund/ Stephen JAFFE- NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

In this photo released by the International Monetary Fund, Managing Director Christine Lagarde (R speaks with Ukrainian President Petro Poroshenko (L) at the IMF Headquarters June 20, 2017 at the IMF Headquarters in Washington, DC. / AFP PHOTO / INTERNATIONAL MONETARY FUND AND AFP PHOTO / STEPHEN JAFFE / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / International Monetary Fund/ Stephen JAFFE- NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

(170620) -- WASHINGTON, June 20, 2017 -- Ukrainian President Petro Poroshenko (L) speaks during a meeting with U.S. Secretary of Defense James Mattis (not in the picture) at the Pentagon in Washington D.C., the United States, on June 20, 2017. ) U.S.-WASHINGTON D.C.-UKRAINE-POROSHENKO-PENTAGON-VISIT TingxShen PUBLICATIONxNOTxINxCHN Washington June 20 2017 Ukrainian President Petro Poroshenko l Speaks during a Meeting With U S Secretary of Defense James Mattis Not in The Picture AT The Pentagon in Washington D C The United States ON June 20 2017 U S Washington D C Ukraine Poroshenko Pentagon Visit TingxShen PUBLICATIONxNOTxINxCHN

(170620) -- WASHINGTON, June 20, 2017 -- U.S. Secretary of Defense James Mattis (R) and Ukrainian President Petro Poroshenko walk to the Pentagon in Washington D.C., the United States, on June 20, 2017. ) U.S.-WASHINGTON D.C.-UKRAINE-POROSHENKO-PENTAGON-VISIT TingxShen PUBLICATIONxNOTxINxCHN Washington June 20 2017 U S Secretary of Defense James Mattis r and Ukrainian President Petro Poroshenko Walk to The Pentagon in Washington D C The United States ON June 20 2017 U S Washington D C Ukraine Poroshenko Pentagon Visit TingxShen PUBLICATIONxNOTxINxCHN

(170620) -- WASHINGTON, June 20, 2017 -- U.S. Secretary of Defense James Mattis (C-R) and Ukrainian President Petro Poroshenko (C-L) walk to the Pentagon in Washington D.C., the United States, on June 20, 2017. ) U.S.-WASHINGTON D.C.-UKRAINE-POROSHENKO-PENTAGON-VISIT TingxShen PUBLICATIONxNOTxINxCHN Washington June 20 2017 U S Secretary of Defense James Mattis C r and Ukrainian President Petro Poroshenko C l Walk to The Pentagon in Washington D C The United States ON June 20 2017 U S Washington D C Ukraine Poroshenko Pentagon Visit TingxShen PUBLICATIONxNOTxINxCHN

(170620) -- WASHINGTON, June 20, 2017 -- U.S. Secretary of Defense James Mattis (L) and Ukrainian President Petro Poroshenko stand during a welcome ceremony at the Pentagon in Washington D.C., the United States, on June 20, 2017. ) U.S.-WASHINGTON D.C.-UKRAINE-POROSHENKO-PENTAGON-VISIT TingxShen PUBLICATIONxNOTxINxCHN Washington June 20 2017 U S Secretary of Defense James Mattis l and Ukrainian President Petro Poroshenko stand during a Welcome Ceremony AT The Pentagon in Washington D C The United States ON June 20 2017 U S Washington D C Ukraine Poroshenko Pentagon Visit TingxShen PUBLICATIONxNOTxINxCHN

(170620) -- WASHINGTON, June 20, 2017 -- U.S. Secretary of Defense James Mattis (1st R) speaks during a meeting with Ukrainian President Petro Poroshenko (not in the picture) at the Pentagon in Washington D.C., the United States, on June 20, 2017. ) U.S.-WASHINGTON D.C.-UKRAINE-POROSHENKO-PENTAGON-VISIT TingxShen PUBLICATIONxNOTxINxCHN Washington June 20 2017 U S Secretary of Defense James Mattis 1st r Speaks during a Meeting With Ukrainian President Petro Poroshenko Not in The Picture AT The Pentagon in Washington D C The United States ON June 20 2017 U S Washington D C Ukraine Poroshenko Pentagon Visit TingxShen PUBLICATIONxNOTxINxCHN

(170620) -- WASHINGTON, June 20, 2017 -- Ukrainian President Petro Poroshenko (2nd L) speaks during a meeting with U.S. Secretary of Defense James Mattis (not in the picture) at the Pentagon in Washington D.C., the United States, on June 20, 2017. ) U.S.-WASHINGTON D.C.-UKRAINE-POROSHENKO-PENTAGON-VISIT TingxShen PUBLICATIONxNOTxINxCHN Washington June 20 2017 Ukrainian President Petro Poroshenko 2nd l Speaks during a Meeting With U S Secretary of Defense James Mattis Not in The Picture AT The Pentagon in Washington D C The United States ON June 20 2017 U S Washington D C Ukraine Poroshenko Pentagon Visit TingxShen PUBLICATIONxNOTxINxCHN