Russia’s Permanent Representative to the United Nations Vitaly Churkin died on Monday at the age of 64, the Russian Foreign Ministry said, TASS reports.

“The Russian Foreign Ministry deeply regrets to announce that Russia’s Permanent Representative to the United Nations Vitaly Ivanovich Churkin has died suddenly in New York on February 20, a day before of his 65th birthday,” the ministry said.

“The outstanding Russian diplomat died in harness,” the ministry said. “We offer sincere condolences to the family of Vitaly Ivanovich Churkin.”

According to Churkin’s first deputy Pyotr Ilyichev, “the loss suffered by Russia is hard and irreparable.”

“He devoted all his life to protecting the interests of Russia, being at the cutting edge and holding most difficult positions,” Ilyichev told a session of the United Nations Trusteeship Council.