Following a briefing by senior UN officials recently returned from Ukraine, a rather undiplomatic debate erupted Wednesday in the UN Security Council between Russia's ambassador and other members of the council as well as the envoy from Kiev.
U.S. President Barack Obama said on Wednesday that the United States would not take military action in Ukraine against Russia.
U.S. President Barack Obama and German Chancellor Angela Merkel condemned on Tuesday Russia's moves to formally annex Crimea.
The Crimean parliament declared independence from Ukraine on Monday, after official results showed 96.77 percent of Crimean voters chose to join Russia in Sunday's referendum.
Russian President Vladimir Putin has signed a decree to recognize Crimea as a sovereign and independent state, the Kremlin press service said Monday.
Russian President Vladimir Putin told his U.S. counterpart Barack Obama in an early Monday call that the Crimea referendum was totally legal, while the White House rejected the results.
President Barack Obama said on Sunday the United States will not recognize the Crimean referendum, vowing to impose fresh sanctions on Russia.
U.S. Secretary of State John Kerry on Thursday threatened "a very serious series of steps" against Russia with the European Union in response to Crimea's vote on Sunday to break away from Ukraine.
Yurii Klymenko, permanent representative of Ukraine to the UN, on Tuesday reiterated that the upcoming referendum on Crimea's status scheduled on March 16 "is illegitimate under the constitution of Ukraine."
The proposed upcoming referendum in Crimea would violate Ukraine's Constitution and the international law, and any discussion on the future of Crimea should include the Ukrainian government, U.S. President Barack Obama said Thursday.