Ukraine’s president has adopted a cautious approach over the Boeing 737-800 crash in Iran, as evidence mounts that the aircraft was brought down by a missile strike.

President Volodymyr Zelensky stresses that the theory of a surface-to-air missile attack has not been confirmed but adds that it has not been ruled out.

He is urging international allies to submit whatever data is available on the 8 January crash to support the investigation commission probing the fatal loss of the Ukraine International Airlines aircraft.

Some 45 Ukrainian personnel are participating in the investigation which, under ICAO standards, is being led by Iran.

“Given the recent statements by the leaders of the states to the media, we call on all international partners, especially the governments of the USA, Canada and the UK, to submit data and evidence relating to the disaster for the use by the commission of inquiry,” says Zelensky.

All nine crew members of the aircraft were Ukrainian, and Ukrainian citizens were among the 167 passengers of the Kiev-bound flight.

Several Canadian passengers were on board and Canadian prime minister Justin Trudeau gave a forthright statement on 9 January, claiming that there was strong evidence that an inadvertent missile attack had been responsible for the crash.

Zelensky says he plans to discuss the investigation with US secretary of state Mike Pompeo. ”Our goal is to establish the undeniable truth,” he says. “We consider it a responsibility of the entire international community.”