Iranian Foreign Minister Javad Zarif on Saturday also blamed the action of Iranian armed forces on U.S. "adventurism."

"A sad day. Preliminary conclusions of internal investigation by Armed Forces: Human error at time of crisis caused by US adventurism led to disaster," Zarif tweeted.

"Our profound regrets, apologies and condolences to our people, to the families of all victims, and to other affected nations," he said.

The chief of Iran's Aviation Organization on Friday had "vehemently" rejected reports that an Iranian missile had hit the Ukranian passenger plane in Tehran's airspace.

Xinhua