The British ambassador to the UN, Matthew Rycroft, has expressed "deepest condolences to the family and colleagues" of Russia’s UN Ambassador Vitaly Churkin. According to him, Churkin was "a diplomatic giant and wonderful character".

"Absolutely devastated to hear that my friend & colleague Vitaly Churkin has died," Matther Rycroft wrote on his Twitter account. "A diplomatic giant & wonderful character. RIP," the diplomat wrote.

'Diplomatic maestro and deeply caring man'

The United States’ former Ambassador to the United Nations, Samantha Power, said she was devastated by the death of Churkin. 

"Devastated by passing of Russian UN Ambassador Vitaly Churkin. Diplomatic maestro and deeply caring man who did all he could to bridge US-Russia differences," she wrote on Twitter.

'Impossible to replace'

Churkin was irreplaceable as Russia’s voice in a key international organization, Deputy Foreign Minister Sergey Ryabkov told TASS.

"Of course, it is a huge loss. It will be impossible, very difficult to replace him as a symbol of Russia’s foreign policy and Russia’s voice on a key international platform in the Security Council," the high-ranking diplomat said.

"Churkin was as a rock, against which attempts of our enemies to undermine all that makes the glory of Russia break," Ryabkov said.

'Tremendous loss for all of us'

The death of Churkin is a colossal loss for the Russian diplomatic community, Permanent Representative to Vienna-based international organizations Vladimir Voronkov has told TASS.

"We have maintained contacts quite often in the recent years, and that is why this news has hit like a ton of bricks. This is a tremendous loss for all of us, a strong blow," Voronkov said.

The diplomat said "he was certainly number one among those who currently work as permanent representatives to international organizations".

"He was best known for highest working capacity, he was a very concentrated person, capable of finding a way out of every situation," the diplomat added.

'Outstanding man and strong personality'

The death of Churkin is a tragedy, he was admired by all opponents, he took to heart all he was doing, Russian Foreign Ministry spokeswoman Maria Zakharova told Rossiya 24 television on Monday.

"This is a tragedy for our ministry and for the Russian diplomatic community," she said. "He was a great professional, an outstanding man and a strong personality who took to heart all he was doing," Zakharova said.

She said Churkin used to work almost round-the-clock, which surprised people and excited admiration.

"He is a person admired not only by those who loved him, his opponents also admired him," the spokeswoman said.

"He came to work in the morning, entered his office, began to work and did not go out anymore. Watching how he works, what volumes (of information) he passed through his head and through his heart, it is surprising. What happened was complete surprise for all," she told the Rossiya 1 TV channel later.

'Big loss'

The sudden death of Vitaly Churkin is a big loss, Russia’s mission to the United Nations office in Geneva and other Geneva-based international organizations said on Monday. 

"We are mourning over the tragic death of Ambassador Vitaly Churkin who represented Russia in New York. It is a big loss. We offer our condolences to his family," the mission said on Twitter.

'Sad news'

US Department of State's Acting Spokesperson Mark Toner has said the news about the death of Churkin is "the sad news".

The United States’ embassy in Moscow extended its condolences over the passing of Churkin.

"Our thoughts and prayers are with the family and friends of Vitaly Ivanovich Churkin," the embassy said on its official Twitter account on Monday.

The Russian Embassy in Washington said the death of the Russian permanent representative to the UN was "a great loss for the Russian diplomatic community".

'One of Russia's most eminent diplomats' 

With Ambassador Vitaly Churkin Russia has lost one of its most eminent diplomats, Federica Mogherini, High Representative for Foreign Affairs and Security Policy, Vice-President of the European Commission, said late on Monday. She expressed her condolences in a letter sent to Russia’s Foreign Minister Sergey Lavrov.

"With Ambassador Vitaly Churkin, the Russian Federation has lost one of its most eminent diplomats. At various occasions, I also personally appreciated his vast experience and his openness. I wish to express my heartfelt condolences to his family and the Russian Foreign Ministry on his untimely passing," she said as quoted by the press release of the European External Action Service.

"As the Russian Permanent Representative to New York he played a leading role on the UN Security Council for more than 10 years. He was an important interlocutor also for the European Union on the many issues that are of key interest to the Union at the United Nations, including on issues where the EU and the Russian Federation did not always see eye-to-eye," according to the press release.

'A real tragedy'

Vitaly Churkin, who died in New York on Monday, was a unique diplomat so it will be hard to replace him, Russian Federation Council (upper house of parliament) Speaker Valentina Matviyenko told TASS on Tuesday.

"He will be hard to replace," she said adding that right now it was inappropriate to speak about a possible date when a new ambassador could be appointed.

According to Matviyenko, Churkin’s death "is a real tragedy." "He was a true diplomat, representative of the traditional Russian school of diplomacy, and a smart man," Matviyenko said noting that Churkin was also "a man of great capacities."

"He died while on duty. The atmosphere in the Security Council has been tense recently and he had to be tough to advocate Russia’s position. He was in constant strain so his heart failed him," the Federation Council speaker said.

"I regret his death very much and would like to convey my condolences to his family, friends and his colleagues at the Foreign Ministry," Matviyenko added.

Loss for Russia and the UN

The sudden death of Vitaly Churkin is a loss for Russia and the UN, Chinese Foreign Ministry Spokesman Geng Shuang said on Tuesday.

"His death was unexpected," the Chinese diplomat said. "This is a loss for Russia and the UN."

Chinese Foreign Minister Wang Yi, in turn, has sent a message to Russia’s top diplomat Sergey Lavrov saying that "Vitaly Churkin was a preeminent Russian diplomat." While serving as Russia’s permanent representative to the United Nations, "he did a lot of highly effective work to boost Russian-Chinese cooperation within the UN and on other platforms," the message reads.

"We convey our deepest condolences to the family of Ambassador Vitaly Churkin and the entire Russian Foreign Ministry," the message adds.

The Chinese foreign minister also hoped that China and Russia would continue to strengthen cooperation within the UN in order to maintain justice, peace and order.

Vitaly Churkin died on February 20, a day before his 65th birthday. He had been Russia’s UN ambassador since April 8, 2006, representing the country in the United Nations Security Council.

Churkin was born in Moscow on February 21, 1952 into the family of an aviation design engineer. He has been Russia’s Ambassador to the United Nations since April 8, 2006.