The UN General Assembly on Monday will open debate on a draft resolution condemning Russia's annexation of four Ukrainian regions, as Western powers seek to underscore Moscow's international isolation.
The decision to bring the matter before the General Assembly, where the 193 UN members have one vote each -- and no one wields veto power -- was taken after Russia used its veto in a Security Council meeting September 30 to block a similar proposal.
"It's extremely important," said Olof Skoog, who, as EU ambassador to the world body, drafted the text in cooperation with Ukraine and other countries.
"Unless the UN system and the international community through the General Assembly react to this kind of illegal attempt, then we would be in a very, very bad place," the Swedish diplomat told reporters.
A failure by the General Assembly to act -- a vote is expected no sooner than Wednesday -- would give "carte blanche to other countries to do likewise or to give recognition to what Russia has done," he added.
A draft of the resolution 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 that these actions have "no validity under international law."
It calls on all states, international organizations and agencies not to recognize the annexations, and demands the immediate withdrawal of Russian troops from Ukraine.
In response, Russia has addressed a letter to all member states in which it attacks "Western delegations" whose actions "have nothing to do with protection of international law and the principles of the UN Charter."
"They only pursue their own geopolitical objectives," said the letter, signed by Russian ambassador Vassily Nebenzia.
He denounced the "huge pressure" he said the United States and its allies were placing on other member states.
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.
'A bit of desperation'
"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 the administration of US President Joe Biden told reporters, speaking on grounds of anonymity.
"It does suggest a bit of desperation."
Such a procedure would first require a vote of the member states -- and not by secret ballot, according to General Assembly spokeswoman Paulina Kubiak.
The UN secretary-general, as the leading defender of the world body's values, bluntly denounced the annexations.
"It stands against everything the international community is meant to stand for," said Antonio Guterres.
"It flouts the purposes and principles of the United Nations. It is a dangerous escalation. It has no place in the modern world. It must not be accepted."
Those remarks, the US official said, "show that this is not really about the West versus Russia."
During the Security Council vote, no other country sided with Russia, though four delegations -- China, India, Brazil and Gabon -- abstained.
Some developing countries have complained that the West is devoting all its attention to Ukraine, and others might be tempted to join them this week.
The vote will provide a clear picture of exactly how isolated Russia has become. Given the high stakes, backers of the draft are going all out to win over potential abstentionists.
"It's going to be tough," a senior European diplomat said, speaking on condition of anonymity.
"For the 2014 annexation resolution of Crimea, there were approximately 100 supportive votes. I think we'll get more this time," he said, estimating total support at 100 to 140 votes.
In March, two earlier General Assembly resolutions condemning the Russian invasion drew, respectively, 141 and 140 votes for, to five against (Russia, Belarus, Syria, North Korea and Eritrea), with 35 and 38 abstentions.
A third vote, in April, to suspend Russia from the UN Human Rights Council, passed but with less unanimity.
There were 93 votes for, 24 against and 58 abstentions.
For the US official, the overarching question this week will be "who's going to vote with Russia," when its objective is "to erase Ukraine from the map."