Iran's three branches of government held an extraordinary meeting on Monday, with First Vice President Mohammad Mokhber representing the executive branch following the death of President Ebrahim Raisi in a helicopter crash, state TV said.

"We will follow the path of President Raisi in fulfilling assigned duties without any interruption," Mokhber said.

The three branches to which state TV referred are the executive, the legislative and the judiciary.

If a president dies in office, the Islamic Republic's constitution says that the first vice president takes over for an interim period of 50 days, with the approval of the Supreme Leader, who has the final say in all matters of state in Iran.

A new presidential election would be held at the end of the 50 days.