There is "no sign" of life coming from President Ebrahim Raisi's helicopter, state TV says.

Reuters has also reported that the helicopter was "completely burned" in the crash, citing an Iranian official.

"President Raisi’s helicopter was completely burned in the crash... unfortunately, all passengers are feared dead," the official said.

Other senior government officials were on board the ill-fated helicopter including the foreign minister.

Meanwhile, Vice President Mohammed Mukhbar is set to be sworn in as new president.

This is pending the approval of the Supreme Leader, following the death of Ebrahim Raisi in a helicopter crash, with the constitution stipulating a new president must be elected within 50 days.