The international community should consider expelling Russia from the United Nations or, at the very least, excluding it from the UN Security Council, where it has a veto, Head of the Office of the President of Ukraine Andriy Yermak said in an op-ed for The New York Times.

He also turned to Western allies and partners of Ukraine with a request to make the costs unbearable for Russia now.

"Article 4 of the 1994 Budapest Memorandum on Security Assurances guaranteed that the United States, Britain and Russia would seek 'immediate' action from the United Nations Security Council 'to provide assistance' if Ukraine "should become a victim of an act of aggression or an object of a threat of aggression in which nuclear weapons are used." Just because the aggressor – Russia – vetoes U.N. Security Council action does not relieve the other parties of the promises they made to Ukraine," Yermak said.