Chinese President Xi Jinping expressed his “deep sorrow” over the death of Iranian president Ebrahim Raisi, who was found dead on Monday after his helicopter crashed in foggy weather over mountainous terrain.

Xi offered his “sincere condolences” to the Iranian government and people, a spokesman for the Foreign Ministry in Beijing said on behalf of the Chinese leader.

Raisi had made “important contributions to maintaining Iran’s security and stability, promoting national development and prosperity, and making positive efforts to consolidate and expand the comprehensive strategic partnership between China and Iran.”

“His unfortunate death is a great loss to the Iranian people and the Chinese people have also lost a good friend,” the spokesman added.

China maintains good political relations with Iran and the two countries have also steadily expanded their economic cooperation.