Iran has invited manufacturer Boeing to take part in the investigation into the Ukrainian passenger jet that crashed outside Tehran on Wednesday, killing all 176 people on board, state media reported.
It comes after intelligence agencies from several Western nations, including the UK, claimed Iran had accidentally shot down the plane with a surface-to-air-missile.
Iran had previously said it would not hand over the recovered black box recorders to "the Americans" or to Boeing, even though it is customary for the manufacturer to be involved in crash investigations.
But in a statement run by the state-operated IRNA news agency, a foreign ministry spokesperson said Iran "has invited both Ukraine and the Boeing company to participate in the investigations". Abbas Mousavi said his country will also welcome experts from other nations whose citizens died in the crash.
Justin Trudeau, the prime minister of Canada - which counts 63 of its citizens among the dead - said late on Thursday he had received intelligence from multiple sources indicating the plane was shot down by an Iranian surface-to-air missile. Similar claims were reported from British and American intelligence officials.
Mr Trudeau said it was possible that the missile firing was unintentional, and that it was still too early to apportion blame. "This reinforces the need for a thorough investigation," he said.
The British foreign secretary Dominic Raab advised British nationals against travelling to Iran "given the body of information that UIA Flight 752 was shot down by an Iranian surface-to-air missile, and the heightened tensions".
The plane crash came just a few hours after Iran launched a ballistic missile attack against two Iraqi military bases housing US troops, part of a retaliation against America for its killing of the top Iranian general Qassem Soleimani.
US officials have suggested that with Iranian air defence systems on high alert amid the confrontation, the passenger jet could have been mistaken for a threat.
Iran's civil aviation authority has denied the possibility that the plane could have been shot down, instead saying the plane appears to have crashed because of technical difficulties.
Additional reporting by agencies
