Russia’s intervention in the Crimean peninsula was requested by ousted Ukrainian President Viktor Yanukovych to establish law and order, a Russian envoy reportedly said Monday at an emergency meeting of the United Nations Security Council, news reports said.

Vitaly Churkin, the Russian envoy to U.N., read from a letter that Yanukovych apparently wrote to Russian President Vladimir Putin, clarifying that Yanukovych had asked for Russia’s intervention in Ukraine because he believed Ukraine was “on the brink of civil war."

"I would call on the president of Russia, Mr Putin, asking him to use the armed forces of the Russian Federation to establish legitimacy, peace, law and order, stability and defending the people of Ukraine," Yanukovych’s letter reportedly said, according to BBC. Yanukovich’s statement also said that “the life and security and the rights of people, particularly in the southeast part in Crimea, are being threatened,” according to Churkin and that there were “open acts of terror and violence.”

Slamming Churkin's defense, Samantha Power, U.S. ambassador to the U.N., reportedly said: "Russian military action is not a human-rights protection mission. It is a violation of international law and a violation of the sovereignty and territorial integrity of the independent nation of Ukraine, and a breach of Russia’s Helsinki commitments and UN obligations."  

Meanwhile, Ukraine circulated a letter asking for international help, claiming that 16,000 Russian troops have been deployed to Crimea, where protests against Ukraine’s new government have raged on since last week after Yanukovych fled Kiev. Churkin defended Russia’s move to station 25,000 troops in Ukraine as being in accordance with law.

“It’s completely legitimate under Russian law, and given the extraordinary situation in Ukraine, this threat and the threat to our compatriots, Russian citizens and the Black Sea Fleet,” Churkin reportedly told a meeting of the UN Security Council in New York, Bloomberg reported.

According to Associated Press, pro-Russian troops controlling the Belbek air base in Crimea fired shots into the air Tuesday as a warning to about 300 Ukrainian soldiers who demanded their job of manning the airfield back. Ukrainian soldiers were also warned by Russian troops of marching against them. Ukraine's interim president, Oleksander Tuchynov, reportedly said that Russia had threatened Ukraine to seize its warships, which Russia denied.

"One might think that Moscow has just become the rapid response arm of the High Commissioner for Human Rights," Power said.

Crimea was given to Ukraine in 1954 by Russian leader Nikita Khrushchev and has a majority population of ethnic Russians. With Russia’s intervention in Ukraine, the U.S., E.U. and other western countries have expressed concerns and warned the Russian government of serious repercussions if it does not pull out its troops from Crimea.

U.S. President Barack Obama said Monday that Russia had violated international law by getting its military involved in Ukraine, and that the action would require Washington to discuss a series of economic and diplomatic sanctions that would isolate Moscow, Al Jazeera reported.