Iran has invited the National Transportation Safety Board, the U.S. accident investigation agency, to participate in the probe of the Ukrainian Boeing commercial jetliner that crashed near Tehran earlier this week.

The NTSB said in a statement Thursday it had received “formal notification” about the crash from the Aircraft Accident Investigation Board of the Civil Aviation Organization of Iran and is sending “an accredited representative to the investigation of the crash.”

Iran has also invited Boeing, the U.S. manufacturer of the plane, to be a part of the investigation team.

It is not, however, immediately clear what level of participation the two U.S. entities would have in the investigation because of the U.S. sanctions placed on Iran and the heightened tensions between the two countries.

Ukraine is also taking part in the investigation.

A color-infrared view shows the area where an Ukraine International Airlines plane crashed after takeoff from Iran’s Imam Khomeini airport, on the outskirts of Tehran, Maxar’s WorldView-2 satellite image taken Jan. 9, 2020.

The latest development comes as U.S. President Donald Trump publicly voiced suspicion that Iran may have accidentally shot down the Ukrainian airliner.

“Somebody could have made a mistake on the other side,” said Trump of Ukraine International Airlines Flight 752. “Some people say it was mechanical. Personally, I don’t think that’s even a question.”

Ballistic missile attack

The crash occurred just hours after Iran launched a ballistic missile attack on Iraqi bases housing U.S. soldiers in response to last week’s U.S. drone attack that killed Iranian Quds Force commander Qassem Soleimani.

Iranian officials have maintained the Boeing 737-800, at an altitude of 2,400 meters, suffered a catastrophic engine failure early Wednesday, local time. All 176 people on the plane bound for Kyiv died, including 63 Canadians.

Mourners attend a vigil at University of Toronto student housing for the victims of a Ukrainian passenger jet, which crashed in Iran, in this still image taken from a video, in Toronto, Ontario, Canada, Jan. 8, 2020.

Government sources have told VOA that U.S. officials have examined satellite data and imagery leading them to believe the airliner, just after taking off from Tehran, was hit by a Russian-made surface-to-air missile after being targeted accidentally.

A U.S. official confirmed to VOA that he is confident the plane was shot down by Iran.

“At some point they’ll release the black box. Ideally, they’ll get it to Boeing,” Trump added in remarks to reporters in the White House Roosevelt Room Thursday.

Video of the aircraft shows it breaking up in the air in a fireball over Iran.

The head of Iran’s of Civil Aviation Organization denies the plane could have been hit by a missile.

“Scientifically, it is impossible that a missile hit the Ukrainian plane and such rumors are illogical,” ISNA quoted Ali Abedzadeh as saying.

The New York Times posted video on its website late Thursday that the newspaper identified as “verified video showing the moment a Ukrainian airliner was hit in Iran.” The Times said the video, provided by Maxar Technologies, appeared to show a missile hitting a plane, which did not explode immediately. The Times said the aircraft turned back “toward the airport ablaze before it exploded.”

Canadian Prime Minister Justin Trudeau speaks to the press, Jan. 9, 2020, in Ottawa, Canada. He said Canada had intelligence from multiple sources indicating that a Ukrainian airliner that crashed near Tehran was mistakenly shot down by Iran.

Canada and Ukraine

The governments of Ukraine and Canada are not accepting the initial assessment by Iran that the cause of the crash appeared to be a mechanical issue.

Citing what he called “intelligence from multiple sources,” Canadian Prime Minister Justin Trudeau said Thursday that “the intelligence indicates that the plane was shot down by an Iranian surface-to-air missile.”

Trudeau added, “This may well have been unintentional.”

Andriy Shevchenko, Ukraine’s ambassador to Canada, expressed solidarity with Canada.

“We, Ukrainians, share the pain that Canadians feel, and the stories that we see on television there are just as heartbreaking to us as the stories about our flight attendants and our pilots that we see on Ukrainian television,” Shevchenko told VOA’s Ukraine service Thursday. “We just feel that we have to walk through this pain together.”

Asked if Trudeau’s announcement would hinder the investigation, Shevchenko said he wouldn’t speculate.

“I wouldn’t speculate on the reasons of the crash either,” he said, “but I would say that it is in the everyone’s interest, including Iran, to have very good, transparent and genuine investigation into this tragedy. I think that truth and only truth is something that can get us moving forward.”

Flowers and candles are placed in front of the portraits of the flight crew of the Ukraine International Airlines Boeing 737-800 plane that crashed in Iran, at a memorial at the Boryspil International airport outside Kiev, Ukraine, Jan. 8, 2020.

Sixty-three of the crash victims were from Canada, which has more than 200,000 citizens of Iranian descent. It is also popular with Iranian students.

“I’m glad that Prime Minister Trudeau is taking this so seriously, but I was saddened and angry that the evidence points to an Iranian missile being responsible for the crash,” Avideh Montmaen-Far, president of the Council of Iranian Canadians, told VOA’s Persian service.

“I hope Canada and other international experts will be involved in order to ensure the investigation is thorough, because families of the victims deserve truth and closure,” she said.

Oleksiy Danilov, secretary of Ukraine’s Security Council, said there were several working theories regarding the crash, including a missile strike.

“A strike by a missile, possibly a Tor missile system, is among the main [theories], as information has surfaced on the internet about elements of a missile being found near the site of the crash,” he told reporters.

Britain urges full investigation

In Britain, government officials told reporters it is looking into “very concerning” reports the plane had been struck by a surface-to-air missile.

Following a phone call Thursday between British Prime Minister Boris Johnson and Ukraine President Volodymyr Zelenskiy, the British government said there needs to be “a full, credible and transparent investigation in what happened.” But British officials added that they did not think the downing of the jet was intentional.

The global security risk company IHS Markit issued a briefing Thursday claiming that the UIA flight was hit by an SA-15 missile fired by a unit of Iran’s Islamic Revolutionary Guard Corps.

Security officers and Red Crescent workers are seen at the site where the Ukraine International Airlines plane crashed after takeoff from Iran’s Imam Khomeini airport, on the outskirts of Tehran, Iran, Jan. 8, 2020.

Ukraine’s deputy foreign minister said his government has sent a team of experts who are on the ground in Iran, working with their Iranian counterparts to sift through the crash debris for evidence of the cause.

“Our priority is that all the pieces of information should be collected and preserved,” Sergiy Kyslytsya told a small group of reporters in New York. “On the black boxes, there are rules and they should be followed, and I am looking forward to the full cooperation of Iran — it is in their best interest.”

He discouraged speculation and conspiracy theories, saying they would hurt the families of the victims.

“My other concern is that the international protocols, conventions and regulations should be duly implemented when it comes to the investigation,” Kyslytsya said. 

Investigators in Iran said the voice and data recorders from the Boeing 737 aircraft, built in 2016, were recovered from the crash site on the outskirts of the Iranian capital, but that the so-called black boxes were damaged and some data had been lost.

The Convention on International Civil Aviation, to which Iran is a signatory, does not require Tehran to hand over the data recorders to the NTSB or Boeing, Andriy Guck, a Ukraine-based attorney and aviation expert, said.

“There is a duty to investigate,” Guck told VOA’s Ukrainian Service in a phone conversation. “Iran can decide to investigate the black boxes by itself or transfer them to a foreign laboratory. But if the Iranians do not allow anyone else to participate in the examination of the boxes, it will raise doubts about their investigation.”

VOA Pentagon Correspondent Carla Babb, VOA National Security Correspondent Jeff Seldin, U.N. Correspondent Margaret Besheer, Jamie Dettmer, Michael Lipin of VOA Persian, and Tatiana Vorozhko of VOA’s Ukrainian Service contributed to this report.