MOSCOW (AP) — Alexander Darchiev, Russia's ambassador to the United States, died Wednesday at age 66, the Foreign Ministry in Moscow said in an online statement.

It did not disclose where the diplomat died or give a cause of death, saying only that he died “suddenly.”

The statement described Darchiev as “an outstanding diplomat, experienced leader, good comrade and mentor,” as well as a brilliant scholar of U.S. affairs, working “in one of the most important areas of Russian foreign policy.”

The longtime diplomat served as the ambassador to the U.S. since early 2025, according to his profile page on the website of the Russian Embassy in Washington. He succeeded Anatoly Antonov, who was relieved of his duties in late 2024.

Before that, Darchiev headed the Foreign Ministry's departments of North America and the North Atlantic; served as ambassador to Canada; and was a minister-counselor at the Washington embassy.

In February 2025, Darchiev headed Russia's delegation in Istanbul for talks with the United States.

Another Russian diplomat, Moscow's U.N. envoy Vitaly Churkin, died suddenly in February 2017 in New York at age 64. At his death, Churkin was the longest-serving ambassador on the U.N. Security Council, having held the post since 2006. Foreign Minister Sergey Lavrov praised him as an “exceptional professional and people’s diplomat.”

The Russian Foreign Ministry did not give a date or a location for Darchiev's funeral.