Russian Ambassador to the UN Vitaly Churkin died at the age of 64, just a day before his 65th birthday, in New York on Monday.

"A prominent Russian diplomat has passed away while at work. We'd like to express our sincere condolences to Vitaly Churkin's family," Russian Ministry of Foreign Affairs said in a statement available on its official website.

Russia's Deputy Permanent Representative Petr Iliichev said about Churkin that he kept working "till the very end."

"The loss that Russia has suffered is irreplaceable. Ambassador Churkin kept working till the very last moment. He dedicated all his life to protecting Russia's interests abroad. He was [always] at the front line, taking the most challenging appointments," Iliichev said.

The representative of the UN Secretary-General Farhan Haq said that the UN was shocked by the news, extending their condolences to Moscow: "We mourn ambassador Churkin, he's been such a regular presence here that I'm actually quite stunned and our thoughts go to his family and his government."

Maria Zakharova, Russian Foreign Ministry spokeswoman, took to Facebook to express her grief: "A great diplomat. An extraordinary personality. A brilliant man. We've lost a person very dear to us."

Putin expressed his condolences to the family of late diplomat, as well as to his colleagues in the Foreign Ministry.

"It is with deep sorrow that Russian President Vladimir Putin learned about the death of Vitaly Churkin," Kremlin spokesman Dmitry Peskov said Monday. He added that Putin held Churkin's professionalism and diplomatic talent in high regard.

Following the news of the ambassador's death, the UN began its scheduled meeting with a moment of silence to honor Churkin's memory.

The late ambassador's colleagues took to Twitter to express their condolences as well.

Devastated by passing of Russian UN Amb Vitaly Churkin.Diplomatic maestro &deeply caring man who did all he cld to bridge US-RUS differences — Samantha Power (@SamanthaJPower) February 20, 2017

Absolutely devastated to hear that my friend & colleague Vitaly Churkin has died. A diplomatic giant & wonderful character. RIP — Matthew Rycroft (@MatthewRycroft1) February 20, 2017

No further details concerning the circumstances of Churkin's death are available at the moment.

Vitaly Ivanovich Churkin was born in Moscow in 1952. He graduated from the Moscow State Institute of International Relations in 1974, beginning his decades-long career at the Ministry of Foreign Affairs shortly.

Ambassador Churkin served as Russia's Permanent Representative to the United Nations since 2006. Prior to this appointment, he was Ambassador at Large at the Ministry of Foreign Affairs of the Russian Federation (2003-2006), Ambassador to Canada (1998-2003), Ambassador to Belgium and Liaison Ambassador to NATO and WEU (1994-1998), Deputy Foreign Minister and Special Representative of the President of the Russian Federation to the talks on Former Yugoslavia (1992-1994), Director of the Information Department of the Ministry of Foreign Affairs of the USSR/Russian Federation (1990-1992).

Vitaly Churkin was awarded the Order For Merit to the Fatherland of IV degree in 2012.

He is survived by his wife and two children.