Russia's UN ambassador Vitaly Churkin dies at work

Diplomats from around the world paid tribute to a respected colleague

Russia's ambassador to the United Nations has died.

Vitaly Churkin, who would have celebrated his 65th birthday on Tuesday, died suddenly while at work in New York on Monday, Russia's foreign ministry said in a statement.

The cause of the veteran diplomat's death is unclear.

Mr Churkin had served as ambassador to the UN since 2006, developing a reputation as a steadfast defender of Russian policy.

Russian President Vladimir Putin was "grieved" to learn of the death of a man whose diplomatic talents he "highly esteemed". The foreign ministry also paid tribute to an "outstanding diplomat".

State television's Rossiya24 praised him for "putting his opponents into shock" and leaving them with "nothing to say".

Many of those "opponents" from around the world were also paying their respects to a colleague who they may have not always agreed with, but respected enormously.

British ambassador Matthew Rycroft tweeted that he was "absolutely devastated" to hear of the death of "a diplomatic giant and wonderful character", while Gerard Araud, a former French ambassador to the UN, recalled Mr Churkin as "abrasive, funny and technically impeccable".

US ambassador Nikki Haley said he was a "gracious colleague", adding: "We did not always see things the same way, but he unquestionably advocated his country's positions with great skill."

Her predecessor, Samantha Power, wrote on Twitter that she was "devastated" to hear of the death of a "diplomatic maestro and deeply caring man who did all he could to bridge US-RUS differences".

Ms Power's tribute came despite a clash last year, when the then US ambassador accused Syria, Russia and Iran of bearing responsibility for atrocities in the war-torn country - an accusation Mr Churkin did not take lying down.

"The weirdest speech to me was the one by the US representative who built her statement as if she is Mother Teresa herself," Mr Churkin retorted.

"Please, remember which country you represent. Please, remember the track record of your country."

Mr Churkin, who was born in Moscow, dabbled in acting as a young teenager - appearing in two films about Vladimir Lenin - before attending the prestigious Moscow Institute of International Relations, eventually beginning a career in Russia's foreign ministry.

Before taking up the position with the UN, he served as an envoy to Canada, Belgium and as a special representative to the talks on former Yugoslavia in the early 1990s.