This came as Western powers condemned Moscow's latest attacks and sought to underscore its isolation.
The United Nations General Assembly is set to meet from Monday, hours after Russia launched a deadly barrage of missile strikes at cities across Ukraine.
This came as Western powers condemned Moscow's latest attacks and sought to underscore its isolation.
The United Nations called the urgent meeting to discuss Russia's declared annexation of four partly occupied Ukrainian regions, but the debate was set to be overshadowed by the attacks on Kyiv and other cities in one of the most punishing assaults on Ukraine in months.
Ahead of the General Assembly session, and with tensions at a boiling point, UN Chief, Antonio Guterres described Russia's attacks as an "unacceptable escalation of the war," his spokesman said according to report by Herald Sun.
"The United States strongly condemns Russia's missile strikes today across Ukraine," he said in a statement.
With Putin's actions in the spotlight, UN debate will open on a draft resolution denouncing what has been widely seen in the West as Russia's illegal seizure of Ukrainian land.
The vote is expected no sooner than Wednesday.
The international community will be in "a very, very bad place," the Swedish diplomat told reporters, "unless the UN system and the international community through the General Assembly react to this kind of illegal attempt."
A resolution draft seen by AFP condemns Russia's "attempted illegal annexations" of the Ukrainian regions of Donetsk, Luhansk, Zaporizhzhia and Kherson following "so-called referendums," and it stresses these actions have "no validity under international law."
In response to the resolution, Russia has written to all member states in a letter attacking "Western delegations" whose actions "have nothing to do with protection of international law and the principles of the UN Charter."
Nebenzia said that given the circumstances, the General Assembly should vote by secret ballot -- a highly unusual procedure normally reserved for matters like electing the rotating members of the Security Council.
"It doesn't suggest a high degree of confidence in the outcome if Russia is seeking to obscure the vote count," a senior official in US President Joe Biden's administration told reporters. "It does suggest a bit of desperation."
"It has no place in the modern world. It must not be accepted."
Some developing countries have complained the West is devoting all its attention to Ukraine, and others might be tempted to join them this week.
On Monday, Ukrainian diplomat Dmytro Kuleba issued a plea to African nations to get off the fence.
Russian President Vladimir Putin, had also on Monday warned Ukraine that if it orchestrates any new terrorist attacks on Russia, it “will respond firmly and on a scale corresponding to the threats created against it."
Meanwhile, the Monday's attacks followed a powerful explosion that rocked the Crimean Bridge on Saturday, killing three and causing the partial collapse of the road section, as well as a blaze on the parallel railway span.
While Ukrainian officials did not directly assume responsibility for the explosion, on Sunday Putin claimed that it was the Ukrainian intelligence service that had orchestrated the blast.