He said the other causes for the crash might be a bomb or catastrophic engine explosion.
Malaysia Airlines flight MH17 was shot down over Ukraine by a Russian-made Buk surface-to-air missile in 2015, killing all 298 passengers and crew members, including 38 Australian citizens and residents.
Asked at a briefing in Kiev if the Iran flight could have been downed by a missile, Ukraine’s Prime Minister Oleksiy Honcharuk cautioned against speculation until an investigation was finished.
There were 82 Iranians, 63 Canadians, 11 Ukrainians and 10 Swedish nationals on board the doomed flight, as well as four Afghans, three Germans and three Britons.
The plane, fully loaded with fuel for its 2300-kilometre flight, climbed to just short of 8000 feet before it lost all communication with ground control.
A preliminary report by Iran’s civil aviation authority said the pilots never made a radio call for help. The report also claimed the plane was attempting to turn back to the airport when it caught fire and exploded on impact.
The report also confirmed that black boxes and cockpit communications from the plane had been recovered but were damaged.
Ukraine has dispatched a team of experts, including officials who worked on the MH17 disaster, to the Iran crash site.
“Our priority is to establish the truth and those responsible for this terrible catastrophe,” President Volodymyr Zelensky said.
Canadian Prime Minister Justin Trudeau said his government would work closely with partners to “ensure this crash is thoroughly investigated and Canadians’ questions are answered”.
The stand-off between the US and Iran threatens to hamper the investigation into the tragedy, given that Boeing, the plane’s manufacturer, is a US company.
Ali Abedzadeh, the head of Iran’s Civil Aviation Organisation, told the semi-official Mehr News Agency that the plane’s black boxes would not be handed to Boeing.
Ukraine International Airlines said the doomed plane was built in 2016 and had been serviced just two days before it crashed.
Bevan Shields is the Europe correspondent for The Sydney Morning Herald and The Age.