Hopes are fading that Iranian President Ebrahim Raisi and his foreign minister have survived a helicopter crash in mountainous terrain and icy weather, an Iranian official said on Monday after search teams located the wreckage.

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

Rescue teams fought blizzards and difficult terrain through the night to reach the wreckage in East Azerbaijan province in the early hours of Monday.

“We can see the wreckage and the situation does not look good,” the head of Iran’s Red Crescent, Pirhossein Kolivand, told state TV.

“With the discovery of the crash site, no signs of life have been detected among the helicopter's passengers.”

Iranian state media said images from the site showed the helicopter crashed into a mountain peak, although there was no official word yet on the cause of the crash.

Raisi, 63, was elected president in 2021, and since taking office has ordered a tightening of morality laws, overseen a bloody crackdown on anti-government protests and pushed hard in nuclear talks with world powers.

Iranian Supreme Leader Ayatollah Ali Khamenei, who holds ultimate power with a final say on foreign policy and Iran's nuclear programme, had earlier sought to reassure Iranians, saying there would be no disruption to state affairs.

A Turkish drone identified a source of heat suspected to be the helicopter's wreckage early on Monday and had shared the coordinates of the possible crash site with Iranian authorities, Anadolu news agency said on X.

State news agency IRNA said Raisi was flying in a U.S.-made Bell 212 helicopter.

The chief of staff of Iran's army ordered all resources of the army and the elite Revolutionary Guards to be put to use in search and rescue operations.

Earlier, the national broadcaster had stopped all regular programming to show prayers being held for Raisi across the country.

In the early hours of Monday, it showed a rescue team, wearing bright jackets and head torches, huddled around a GPS device as they searched a pitch-black mountainside on foot in a blizzard.

“We are thoroughly searching every inch of the general area of the crash," state media quoted a regional army commander as saying. "The area has very cold, rainy, and foggy weather conditions. The rain is gradually turning into snow."