Russia's ambassador to the UN, Vitaly Churkin (pictured), read from the letter at the United Nations, saying deposed President Yanukovych had requested military aid from President Vladimir Putin on Saturday.

Russia had called Monday's Security Council meeting on Ukraine, the third in the past four days, saying it wanted to explain its stance after its parliament on Saturday approved the use of force in Ukraine.

"Under the influence of Western countries, there are open acts of terror and violence," Churkin read aloud from the document. "People are being persecuted for language and political reasons. So in this regard 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 to defend the people of Ukraine."

US ambassador to the UN Samantha Power said there was no evidence of danger to ethnic Russian or pro-Russian communities in Ukraine.

"Russian military action is not a human rights protection mission. It is a violation of international law," Power said. "Russian mobilization is a response to an imaginary threat… Military action cannot be justified on the basis of threats that haven't been made and that aren't being carried out."

British UN ambassador Mark Lyall Grant was similarly critical, also referring to the Russian deployment in Crimea as a "flagrant breach" of international law. "We can see absolutelely no justification for these actions," he said.

The US and UK have also withdrawn their delegations scheduled to travel to the Winter Paralympics in Sochi.

Kyiv's UN envoy, Yuriy Sergeyev, told the council that Russia had deployed roughly 16,000 troops to Ukraine's Crimea territory since February 24, saying these were in addition to the soldiers Russia stations in the region under bilateral agreements to service its Black Sea Fleet.

EU calls emergency summit

European Council President Herman von Rompuy on Monday scheduled a summit of the EU's 28 leaders for Thursday, saying they would "discuss the latest developments in Ukraine and how to facilitate the necessary de-escalation of the situation."

The bloc's foreign ministers, who convened on Monday, said in a joint statement that Brussels would also consider "consequences for bilateral relations of the EU and Russia" in the absence of efforts from Moscow to calm the Crimean crisis.

German Foreign Minister Frank-Walter Steinmeier, who has described the tension as "Europe's worst crisis since the fall of the Berlin Wall," met his Russian counterpart Sergey Lavrov in Geneva late on Monday. Lavrov had addressed the UN Council on Human Rights earlier in the day, saying Russian intervention was "a question of defending our citizens and compatriots."

US Secretary of State John Kerry was expected to return to Kyiv on Tuesday for talks with interim government leaders and parliamentarians.

The Crimean standoff also affected money markets on Monday, particularly in Russia. The MICEX stock index shed 10.8 percent of its value and the ruble currency fell to record lows against the euro and the dollar. Germany's DAX was down 3.4 percent on the day, suffering more than Paris' CAC 40 and London's FTSE 100. In the US, all three major indices were able to contain daily losses within 1 percentage point.

msh/lw (AFP, AP, Reuters)