China expressed deep condolences to the family of late Russian UN Ambassador Vitaly Churkin, Russian government and Russia's mission to the UN over his death, a senior Chinese envoy said at a UN Security Council meeting on Tuesday in New York.

We feel shocked and sad about Ambassador Churkin's sudden death and express deep condolence, said Liu Jieyi, China's ambassador to the UN.

Liu described Churkin as a capable, experienced and senior diplomat who has made important contributions to the UN and multilateralism.

"He worked till the end of his life, showing exactly what's dedication and professionalism. He is an outstanding representative of diplomats," Liu said.

The UN Security Council paid tribute to the veteran diplomat before a meeting and ambassadors of 15 council members made speeches in memory of him.

Churkin, who has been Russia's permanent representative to the UN since 2006, died in New York on Monday, one day before his 65th birthday, after becoming ill at work, the Russian Foreign Ministry said. He died reportedly from a heart attack.

UN Secretary-General Antonio Guterres said on Monday that he "learned with shock and sadness" of the death of Churkin.

"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.

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 contributed to this story