Turkish President Recep Tayyip Erdoğan expressed deep grief over the unexpected death of Iranian President Ibrahim Raisi. He said that he remembers Raisi with respect and gratitude. Al-Jazeera news

He said, as Turks, we will stand by our neighbor Iran in this difficult and sad time, as we have done many times before.

Meanwhile, Lebanon and Syria have declared three days of national mourning for Raisi's death. Abdel Fattah Al-Sisi mourned the death of Raisi. Praying for him, he said, May God's mercy be upon the late president of Iran and the deceased and give patience and comfort to their families.

Saudi King Salman bin Abdulaziz also expressed his condolences in a message sent to Iran's new acting president, Mohammad Mokhbar.

As we send our deep and sincere condolences to you and the brotherly people of the Islamic Republic of Iran, let us pray to Almighty Allah to shower them with His immense mercy and forgiveness and grant them peace, a Saudi Press Agency statement said. May his soul rest in peace. Surely we belong to Allah, to Him we shall return.

Syrian President Bashar al-Assad sent a cable to Khamenei expressing 'deep sorrow and condolences' over the helicopter crash. Al-Assad called Raisi's death a 'great loss' and praised his efforts to ensure that the strategic relationship between Syria and Iran remains prosperous.

Supreme Leader Ayatollah Ali Khamenei has named the country's First Vice President Mohammad Mokhbar as acting president after the death of Iranian President Ibrahim Raisi in a helicopter crash.