The UN Security Council is scheduled to meet for the first time over Russia's troop build-up and threatening actions against Ukraine, at the request of the United States.
All key players are expected to square off in public over the possibility of a Russian invasion and its global impact.
US ambassador Linda Thomas-Greenfield said Russia's actions pose "a clear threat to international peace and security and the UN Charter".
Council members "must squarely examine the facts and consider what is at stake for Ukraine, for Russia, for Europe, and for the core obligations and principles of the international order should Russia further invade Ukraine," she said on Thursday, in announcing the meeting.
Russia's deputy UN ambassador Dmitry Polyansky responded angrily, tweeting: "I can't recall another occasion when a SC (Security Council) member proposed to discuss its own baseless allegations and assumptions as a threat to intl (international) order from someone else. Hopefully fellow UNSC members will not support this clear PR stunt shameful for the reputation of UN Security Council."
Mr Polyansky's reaction indicated that Russia may start the meeting asking for a procedural vote on whether it should go ahead.
To block the meeting, Russia would need support from nine of the 15 members.
A senior official in the Biden administration said the United States is in regular contact with council members and is "confident" that there is "more than sufficient support" to hold the meeting.
"It goes right to the heart of the role of the Security Council itself," the official said.
"This preventive diplomacy is exactly what the council is supposed to be doing, and I think member states understand that."
Russia's massing of an estimated 100,000 troops near the border with Ukraine has brought increasingly strong warnings from the West that Moscow intends to invade.
Russia is demanding that Nato should promise never to allow Ukraine to join the alliance, and to stop the deployment of Nato weapons near Russian borders and roll back its forces from Eastern Europe.
Nato and the US said those demands are impossible.
Assuming the meeting goes ahead, the council will first hear a briefing by a senior UN official followed by statements from its 15 members including Russia, the United States and European members France, Ireland, the United Kingdom and Albania. Under council rules, Ukraine will also speak.
China's UN ambassador Zhang Jun, whose country has close ties to Russia, indicated Beijing supports Moscow in opposing a council meeting.
"Both sides have shown willingness to continue their negotiations," he told several reporters on Friday.
"Let them settle the differences through dialogue, through negotiations."
Mr Zhang added that "Russia has said clearly they have no intention to have a war" and the Security Council should "help to deescalate the situation instead of adding fuel to the fire".
The head of Russia's Security Council, Nikolai Patrushev, rejected Western warnings about an invasion on Sunday.
"At this time, they're saying that Russia threatens Ukraine - that's completely ridiculous," he was quoted as saying by state news agency Tass.
"We don't want war and we don't need it at all."
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