TEHRAN - Iranian president Ebrahim Raisi has died in a helicopter crash after it went missing in a mountainous region of northern Iran in foggy weather conditions.

The aircraft went down in between Jolfa and Varzaqan, a region on the border of Azerbaijani exclave Nakhchivan, around 600 kilometers (375 miles) northwest of the Iranian capital Tehran.

It was carrying Raisi, 63, and Iranian foreign minister Hossein Amir Abdollahian following a visit with the Azerbaijani president to discuss an infrastructure project over the Aras River, which separates Iran and Nakhchivan.

The state-run Mehr news agency on Monday announced that the president, foreign minister and East Azerbaijan Province governor Malek Rahmati had been “martyred” shortly after the wreckage of the helicopter was found on the slope of a steep mountain. An official separately told Reuters that the president had died, and an announcement was also made on Iranian state TV.

Earlier, an official with the rescue operation said “President Raisi’s helicopter was completely burned in the crash,” as they ruled out finding any survivors.

Raisi was flying in a US-made Bell 212 helicopter, according to reports. Turkish authorities said drone footage showed a fire some 20km south of the Azerbaijan-Iranian border on the side of the mountain.

Up to 40 rescue teams were involved in the frantic search for Raisi which went on for hours due to fog, rain and dark, Iran’s health minister said. In the early hours of Monday, 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.

Iran’s revolutionary guard, ambulances, surgeons, rangers, drones and dogs were scrambled to the area to find the helicopter crash site.

Before Raisi was found, Iran’s supreme leader Seyyed Ali Hosseini Khamenei said he hoped God would return him to Iran and urged people to pray for his health.

The White House said president Joe Biden had been briefed on reports about the crash, while China and Russia said they were deeply concerned.

The EU had offered its emergency satellite mapping technology in the search for the helicopter.

Indian prime minister Narendra Modi said he was “deeply saddened and shocked by the tragic demise” of Raisi.

“His contribution to strengthening India-Iran bilateral relationship will always be remembered. My heartfelt condolences to his family and the people of Iran. India stands with Iran in this time of sorrow,” Mr Modi wrote on X.

Venezuelan president Nicolas Maduro also expressed his condolences, saying that Raisi was an “unconditional friend” of Venezuela. “A heartfelt hug from the Bolivarian Republic of Venezuela. You, Iran, are an example of dignity, morality and resistance,” he added.

Pakistan announced it would observe a day of mourning and the flag will fly at half mast as a mark of respect for Raisi and his companions. Pakistan prime minister Shehbaz Sharif said he extended his deepest condolences to “Brotherly Iran” on behalf of himself and the Pakistani people and government.