UNITED NATIONS — In the first barometer of global condemnation of Russia’s annexation of Crimea, Ukraine and its Western backers persuaded a large majority of countries in the United Nations General Assembly on Thursday to dismiss the annexation as illegal, even as Russia sought to rally world support for the idea of self-determination.
The resolution, proposed by Ukraine and backed by the United States and the European Union, represented the latest effort to isolate President Vladimir V. Putin of Russia over the annexation, which followed a March 16 referendum in the peninsula that has been internationally regarded as Ukrainian territory.
The resolution garnered 100 votes in favor, 11 votes against, with 58 abstentions. The two-page text does not identify Russia by name, but describes the referendum as “having no validity” and calls on countries not to recognize the redrawing of Ukraine’s borders.
Ukraine’s acting foreign minister, Andriy Deshchytsia, called Russia’s actions “a direct violation of the United Nations Charter.”
Russia said Crimea should not have been part of Ukraine anyway and appealed to another element in United Nations principles: the right of Crimeans to self-determination.
That assertion was disputed by Samantha Power, the United States ambassador, in the debate that preceded the vote. Coercion cannot be the means to self-determination, she argued. “The chaos that would ensue is not a world that any of us can afford,” she said.
The most poignant argument came from Costa Rica. Small states have only the power of international law “to defend our sovereignty,” its ambassador, Eduardo Ulibarri, said. The resolution proposed by Ukraine, he said, would help to reaffirm that power.
The resolution was regarded as an important pressure point on Russia by the United States and European Union, which had been lobbying intensely for its passage. “This is critical for the U.S.-Europe strategy to isolate Putin and condemn him internationally for Russia’s violation of the U.N. Charter in invading Crimea,” said Nicholas R. Burns, a former American diplomat in the Bush administration.
Although the resolution has no enforcement power, it is symbolically significant in the history of General Assembly votes. The United States has rarely corralled a majority of General Assembly members, especially after the American-led invasion of Iraq more than a decade ago.
Mr. Burns added: “It is also, indirectly, a warning to Putin to not go further in invading either Eastern Ukraine or Moldova or else face even greater global criticism.”