In this Sunday, Jan. 14, 2018 photo provided by China's Ministry of Transport, the burning Iranian oil tanker Sanchi is seen partially sunk in the East China Sea off the eastern coast of China. The fire from the sunken Iranian tanker ship in the East China Sea has burned out, a Chinese transport ministry spokesman said Monday, although concerns remain about possible major pollution to the sea bed and surrounding waters. (Ministry of Transport via AP)

In this Sunday, Jan. 14, 2018 photo provided by China's Ministry of Transport, smokes and frames from the burning Iranian oil tanker Sanchi in the East China Sea off the eastern coast of China. The fire from the sunken Iranian tanker ship in the East China Sea has burned out, a Chinese transport ministry spokesman said Monday, although concerns remain about possible major pollution to the sea bed and surrounding waters. (Ministry of Transport via AP)

In this Sunday, Jan. 14, 2018, photo provided by China's Ministry of Transport, a rescue ship sails near the burning Iranian oil tanker Sanchi in the East China Sea off the eastern coast of China. The fire from the sunken Iranian tanker ship in the East China Sea has burned out, a Chinese transport ministry spokesman said Monday, although concerns remain about possible major pollution to the sea bed and surrounding waters. (Ministry of Transport via AP)

This handout picture taken and released on January 12, 2018 by the Transport Ministry of China shows the Chinese firefighting vessel "Donghaijiu 117" spraying foam on the burning oil tanker "Shanchi" at sea off the coast of eastern China. Chinese firefighters spent January 11 struggling to extinguish a blaze on a stricken oil tanker as criticism mounted in Iran over whether enough was being done to locate dozens of its missing crew members. / AFP PHOTO / TRANSPORT MINISTRY OF CHINA / Handout / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / TRANSPORT MINISTRY OF CHINA" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

This handout picture taken and released on January 12, 2018 by the Transport Ministry of China shows the Chinese firefighting vessel "Donghaijiu 117" spraying foam on the burning oil tanker "Shanchi" at sea off the coast of eastern China. Chinese firefighters spent January 11 struggling to extinguish a blaze on a stricken oil tanker as criticism mounted in Iran over whether enough was being done to locate dozens of its missing crew members. / AFP PHOTO / TRANSPORT MINISTRY OF CHINA / Handout / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / TRANSPORT MINISTRY OF CHINA" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

This handout picture taken and released on January 12, 2018 by the Transport Ministry of China shows the Chinese offshore supply ship "Shen Qian Hao" spraying foam on the burning oil tanker "Shanchi" at sea off the coast of eastern China. Chinese firefighters spent January 11 struggling to extinguish a blaze on a stricken oil tanker as criticism mounted in Iran over whether enough was being done to locate dozens of its missing crew members. / AFP PHOTO / TRANSPORT MINISTRY OF CHINA / Handout / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / TRANSPORT MINISTRY OF CHINA" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

This handout photo from the Transport Ministry of China taken and released on January 9, 2018 shows smoke and flames coming from the burning oil tanker 'Sanchi' at sea off the coast of eastern China. China raced to contain oil leaking from an Iranian tanker stricken off its eastern coast on January 9, amid warnings the burning ship could spark an environmental disaster. / AFP PHOTO / TRANSPORT MINISTRY OF CHINA / - / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / TRANSPORT MINISTRY OF CHINA" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

This handout from the Transport Ministry of China taken on January 7, 2018 and released on January 8, 2018 shows the Chinese firefighting vessel "DONGHAIJIU 117" spraying water on the burning oil tanker Sanchi at sea off the coast of eastern China. The Iranian oil tanker ablaze off the Chinese coast is at risk of exploding or sinking, authorities said on January 8, as they reported there was no sign of survivors 36 hours after the vessel erupted in flames. / AFP PHOTO / TRANSPORT MINISTRY OF CHINA / Handout / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / TRANSPORT MINISTRY OF CHINA" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

In this photo provided by Korea Coast Guard, the Panama-registered tanker "Sanchi" is seen ablaze after a collision with a Hong Kong-registered freighter off China's eastern coast Sunday, Jan. 7, 2018. The oil tanker collided with a bulk freighter and caught fire off China's eastern coast, leaving its entire crew of 32 missing, most of them Iranians, authorities said. (Korea Coast Guard via AP)

This handout from the Korea Coast Guard taken and released on January 7, 2018 shows the Panamanian-flagged tanker "Sanchi" on fire after a collision with a cargo ship at sea. Thirty-two people, mostly Iranians, were missing on January 7 after an oil tanker collided with a cargo ship off the coast of east China, the transport ministry said. / AFP PHOTO / KOREA COAST GUARD / handout / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / KOREA COAST GUARD" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

This handout from the Korea Coast Guard taken and released on January 7, 2018 shows the Panamanian-flagged tanker "Sanchi" on fire after a collision with a cargo ship at sea. Thirty-two people, mostly Iranians, were missing on January 7 after an oil tanker collided with a cargo ship off the coast of east China, the transport ministry said. / AFP PHOTO / KOREA COAST GUARD / handout / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / KOREA COAST GUARD" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS