Two U.S. officials say it was “highly likely” that an Iranian anti-aircraft missile downed a Ukrainian jetliner late Tuesday, killing all 176 people on board. The officials, citing U.S. intelligence, spoke on the condition of anonymity to discuss sensitive information.  

Canadian Prime Minister Justin Trudeau also said Thursday that evidence indicates an Iranian surface-to-air missile downed the Ukrainian jetliner late Tuesday but “may have been unintentional.” 

Trudeau said Canadian and allied intelligence supports that theory, but he declined to get into the intelligence specifics. 

According to CBS News, U.S. intelligence picked up signals of radar being turned on and infrared blips of two missile launches were detected. 

A senior Pentagon official and one U.S. senior intelligence official told Newsweek the Pentagon believes the incident was accidental. They said Iran's anti-aircraft missiles were likely active following the country's missile attack on two Iraqi bases housing U.S troops. 

When asked about incident at a press conference, President Donald Trump said "I had my suspicions." 

"Somebody could have made a mistake on the other side," he said. Trump said he personally did not believe Iran's claim that it was a mechanical error that brought down the plane. He also denied any U.S. responsibility for the crash.

The crash of the Ukrainian jetliner Wednesday killed 176 people. Officials say the plane was carrying 82 Iranians, 63 Canadians and 11 Ukrainians. It was headed to Kyiv, Ukraine.

Iran investigators say the crew of Ukrainian Airlines Boeing 737-800 never made a radio call for help and were trying to turn back to the airport when the plane went down.

Ukrainian President Volodymyr Zelenskiy on Thursday and called for “a full, credible and transparent investigation into what happened,” according to the Associated Press. He said Iranian President Hassan Rouhani assured him of Iran's "full cooperation" in the investigation. The two leaders spoke by phone Thursday, according to the Associated Press. 

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The crash happened hours after Iran launched missiles at two Iraqi bases that house U.S. forces. It was in response to the U.S. killing of a top Iranian general.

Iranian officials have blamed mechanical trouble for the crash and have dismissed suggestions that the plane may have been accidentally shot down in the missile attack.

Ukrainian officials agreed with the assessment that the plane was downed by mechanical trouble, but later backed away from that, according to The Associated Press.

When asked at a press conference if he could definitively say the plane was not shot down, Canadian Prime Minister Justin Trudeau said he could not.

BBC News reports Iran says it will not hand over flight recorders recovered from the crash to Boeing or the U.S.