UNITED NATIONS - China offers deep condolences to Russia over the death of its ambassador to the United Nations, Vitaly Churkin, a Foreign Ministry spokesman said on Tuesday.

Calling Churkin an excellent diplomat who deserved great respect, ministry spokesman Geng Shuang said the ambassador's death is a loss not only for Russia, but also for the UN's work.

"We feel shocked and sad about Ambassador Churkin's sudden death and express deep condolence," Geng said in Beijing.

Churkin died in New York on Monday after becoming ill at work, the Russian Foreign Ministry said. His sudden death, apparently from a heart attack, occurred on the eve of his 65th birthday.

UN Secretary-General Antonio Guterres said on Monday that he "learned with shock and sadness" of the death of Churkin, who had been Russia's permanent representative to the UN since 2006 and was the longest-serving ambassador on the 15-member UN Security Council.

"Ambassador Churkin was a uniquely skilled diplomat, a powerful orator with great wit, and a man of many talents and interests," Guterres said in a statement issued on Monday night.

Describing him as an outstanding diplomat, the secretary-general noted that Churkin served his country "with distinction through some of the most challenging and momentous periods of recent history".

For more than a decade, Churkin was "a forceful presence on the Security Council," he said.

Also on Monday, former UN secretary-general Ban Ki-moon said in a statement issued in Seoul, South Korea, that he was "shocked and truly saddened" to learn of Churkin's death.

"During my 10 years as secretary-general, it was a privilege to work with him and watch him represent the Russian Federation with such passion and dedication. He was an outstanding diplomat and an intellectual star," said Ban, who was succeeded by Guterres on Jan 1 after two five-year terms as the UN chief.

The Russian Foreign Ministry said in a statement issued in Moscow: "A prominent Russian diplomat has passed away while at work. We'd like to express our sincere condolences to Vitaly Churkin's family."

Churkin, who was born on Feb 21, 1952, in Moscow, served as ambassador-at-large at the Russian Foreign Ministry from 2003 to 2006, before his appointment to the UN.

He was Russian ambassador to Canada from 1998 to 2003, and to Belgium from 1994 to 1998.

Xinhua-china Daily