Vladimir Putin has issued a statement after Ayatollah Ali Khamenei was killed in a US-Israeli strike on Saturday. The Russian president wrote directly to Iran’s new acting leader, President Masoud Pezeshkian, expressing condolences and accusing Washington and Tel Aviv of carrying out an attack that violated international law and risked destabilising the entire Middle East.

In the message released by the Kremlin, Putin described the killing of Khamenei and several of his family members as an “assassination” committed in “cynical violation of all norms of human morality and international law”. He praised Khamenei as “an outstanding statesman” and said he had played a major role in strengthening ties between Moscow and Tehran, calling the relationship a “comprehensive strategic partnership”.

Putin's letter to Pezeshkian read: "Dear Mr. President. Please accept my deepest condolences on the assassination of the Supreme Leader of the Islamic Republic of Iran, Seyyed Ali Khamenei, and his family members, committed in cynical violation of all norms of human morality and international law.

"In our country, Ayatollah Khamenei will be remembered as an outstanding statesman who made an enormous personal contribution to the development of friendly Russian-Iranian relations, elevating them to the level of a comprehensive strategic partnership.

"Please convey my sincere sympathy and support to the family and friends of the Supreme Leader, the government and all the people of Iran."

Russia has backed Iran diplomatically for years and has publicly condemned the US-Israeli operation, which struck multiple sites across Iran early on Saturday morning.

Moscow’s foreign ministry issued a strongly worded statement warning that the attack risked pushing the region towards a “humanitarian, economic and, possibly, radiological catastrophe”.

It claimed the strikes were deliberate and planned well in advance, describing them as an “unprovoked act of armed aggression against a sovereign and independent member state of the UN”.

The statement also criticised the US and Israel for conducting strikes while international negotiations were still taking place.

“It is reprehensible that the attacks are again being carried out under the cover of a resumed negotiation process,” the ministry said, arguing that Israel had previously indicated it was not seeking a direct military confrontation.

Moscow said the international community, including the UN and the International Atomic Energy Agency, must issue a clear response, accusing the US and Israel of “destroying peace, stability and security in the Middle East”.

It also warned that attempts to target nuclear-related sites were “unacceptable” and would weaken global non-proliferation efforts.

Russia claims Washington and Tel Aviv are pursuing wider political objectives, arguing that the military action represents an attempt to “destroy the constitutional order and eliminate the leadership of an undesirable state that refused to submit to military dictatorship and hegemony”.

It added that any escalation risked encouraging other countries in the region to pursue more advanced weapons in response.

The statement concluded with a call for a rapid diplomatic reset. “We demand that the situation be immediately returned to the track of political and diplomatic settlement,” the ministry said.

“Russia, as before, is ready to assist in the search for peaceful solutions based on international law, mutual respect and a balance of interests.”