MOSCOW - Killing Iran's Supreme Leader Ayatollah Ali Khamenei was a blatant violation of human moral principles and international law, Russian President Vladimir Putin said Sunday.

Putin said that Khamenei will be remembered in Russia as an outstanding statesman who helped raise bilateral ties to the level of a comprehensive strategic partnership.

Putin expressed deep condolences over the killing of Khamenei and members of his family, hoping that his sincere condolences would be conveyed to the family and loved ones of the late Iranian leader, as well as to the government and people of Iran.

Iran's state media confirmed Sunday that Khamenei was killed in US-Israeli attacks on Saturday.

Also on Sunday, the Russian Ministry of Foreign Affairs said Moscow expressed indignation and deep regret about the deaths of Khamenei, several members of his family and senior Iranian officials in the US and Israeli airstrikes.

"Russia firmly and consistently condemns the practice of political assassinations and the targeting of leaders of sovereign states, which runs counter to the basic principles of civilized interstate relations and grossly violates international law," the ministry said in a statement.

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As a result of ongoing hostilities, the number of civilian casualties continues to rise and serious damage is being inflicted on civilian infrastructure, the statement said.

Russia calls for immediate de-escalation, a cessation of hostilities, and a return to the political and diplomatic process in order to resolve existing problems on the basis of the UN Charter and the Treaty on the Non-Proliferation of Nuclear Weapons, it said.

"The legitimate interests of all Gulf states must be duly taken into account," it added.