Russia's Ambassador to the United States, Alexander Darchiev, died suddenly on Wednesday at the age of 66, the Russian Foreign Ministry announced.
In an official statement, the ministry confirmed that Darchiev had passed away on November 11, without providing details about the circumstances of his death or its cause.
"We have lost an outstanding diplomat, an experienced leader, a kind colleague and a mentor," the ministry said.
Describing Darchiev as "an exceptional professional and a distinguished expert on the United States," the ministry noted that he had worked in one of the most challenging areas of Russian diplomacy.
"We extend our deepest and most heartfelt condolences to Alexander Darchiev's family and loved ones," the statement added.
Darchiev was appointed ambassador to Washington by Russian President Vladimir Putin in March 2025, replacing Anatoly Antonov. His appointment came as Moscow and Washington began efforts to improve relations following President Donald Trump's return to the White House.
A veteran Russian diplomat known for his sharp criticism of Western policies, Darchiev had previously served at Russia's embassy in Washington during the late 2000s.
He also spent six years as Russia's ambassador to Canada and subsequently headed the Russian Foreign Ministry's North American Department for four years.
Neither the Kremlin nor US officials had immediately issued statements regarding his death.