"In case of death, dismissal, resignation, absence or illness for a period exceeding two months of the President of the Republic, the First Vice-President of the Republic assumes the position", according to article 131 of the Constitution of the Islamic Republic of Iran, quoted by international agencies, hours after the incident involving Ebrahim Raisi.

This change must have the "consent of the Supreme Leader" of the country, 'ayatollah' Ali Khamenei, who has already appealed today to the Iranians "not to worry" while the searches continue.

"The people of Iran should not worry, there will be no interruption in the country's functions", said Khamenei in a meeting with the families of the members of the Revolutionary Guard in Tehran, according to the IRNA news agency.

The current first vice-president of Iran is Mohammad Mokhber, 68, who has been in office since 2021 and previously led the powerful conglomerate "Execution of Imam Khomeini's Order" (EIKO). For these functions, he has been the target of sanctions by the United States since 2021.

In the event of the death of the first vice-president or other circumstances that prevent him from exercising his functions, as well as in the event that the deceased President does not have a first vice-president, the supreme leader appoints another person.

President Raisi remains missing, as does Iranian Foreign Minister Hossein Amir-Abdollahian, after their helicopter crashed in the Kalibar and Warzghan area, in the East Azerbaijan province, in the northwest of the country.

The accident occurred when the delegation was returning from the border with Azerbaijan, where Raisi inaugurated a dam with his Azeri counterpart, Ilham Aliyev.

The Iranian Army indicated at the last hour that it had located the "exact" position of the helicopter in which Iranian President Ebrahim Raisi was traveling, thanks to a signal from the aircraft and another from the cell phone of one of the crew members.

At least 65 rescue teams are on the ground in search operations that are being hampered by dense fog and heavy rains.

Saudi Arabia, Iraq, Azerbaijan and Russia offered help to Tehran, while US President Joe Biden was informed about the incident, according to the White House, which did not provide further details.

Turkey has already sent 32 rescue teams and six vehicles, and the European Union has activated the Copernicus rapid response mapping service at Iran's request.

Ebrahim Raisi, 63, a hardline cleric, was elected President of Iran in 2021, in a presidential election with the lowest turnout in the history of the Islamic Republic.

His leadership has seen an intensification of the crackdown on activists, women and critics of the regime.

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