The resolution backed by 143 of the 193 UN member states condemns “the organization by the Russian Federation of so-called referendums within the internationally recognized borders of Ukraine" and "the attempted illegal annexation" announced last month of four regions by President Vladimir Putin.
It calls on all UN and international agencies not to recognize any changes announced by Russia to borders and demands that Moscow "immediately and unconditionally reverse" its decisions.
Only Syria, Nicaragua, North Korea, and Belarus joined Russia in voting against the resolution. Thirty-five countries, including Armenia, China, India, South Africa and Pakistan, abstained. Azerbaijan, Iran, Venezuela and Turkmenistan did not vote at all.
U.S. Secretary of State Antony Blinken said the vote showed international unity against Russia and repeated that Washington will never recognize the "sham" referendums.
Russian Foreign Minister Sergei Lavrov on Thursday accused Washington of blackmailing many developing nations to back the non-binding measure.
Moscow last month proclaimed its annexation of four partially occupied regions in Ukraine -- Donetsk, Luhansk, Kherson, and Zaporizhzhya -- after staging what it called referendums. Ukraine and its allies denounced the votes as illegal.
Armenia similarly abstained in March when the UN General Assembly deplored “in the strongest terms” Russia's invasion of Ukraine. The Armenian government has not publicly condemned the Russian military campaign, let alone joined the Western sanctions against Moscow.
Prior to the invasion, Armenia had repeatedly voted against General Assembly resolutions condemning Russia’s annexation of Crimea and upholding Ukrainian sovereignty over the Black Sea peninsula.
Russia has long been the South Caucasus state’s main military and political ally. Relations between Yerevan and Moscow have soured lately, however, because of what Armenian leaders see as a lack of Russian support received by them during and after last month’s Azerbaijani attacks on the Armenian border.