The United States and Russia faced off Monday at the United Nations Security Council over Washington's accusations that Moscow is planning a large-scale invasion of neighboring Ukraine, which the Kremlin has denied.
"The situation we're facing in Europe is urgent and dangerous, and the stakes for Ukraine — and for every U.N. member state — could not be higher," U.S. Ambassador Linda Thomas-Greenfield told council members.
She said the more than 100,000 troops Russia has amassed along Ukraine's border include combat forces and special forces prepared to conduct offensive actions into the former Soviet republic.
"This is the largest — this is the largest — hear me clearly — mobilization of troops in Europe in decades," Thomas-Greenfield said. "And as we speak, Russia is sending even more forces and arms to join them."
She said that included the nearly 5,000 Russian troops "with short-range ballistic missiles, special forces and anti-aircraft batteries" that Moscow had moved into its close ally and neighbor Belarus. There is evidence Moscow plans to increase their number to 30,000 troops by early February, she added.
The U.S. ambassador said Russia's aggression threatens Ukraine, Europe and the international order.
"An order that, if it stands for anything, stands for the principle that one country cannot simply redraw another country's borders by force or make another country's people live under a government they did not choose," she said.
As Thomas-Greenfield spoke, President Joe Biden issued a statement from the White House.
"If Russia is sincere about addressing our respective security concerns through dialogue, the United States and our allies and partners will continue to engage in good faith," Biden said. "If instead, Russia chooses to walk away from diplomacy and attack Ukraine, Russia will bear the responsibility, and it will face swift and severe consequences."
He later told reporters in the Oval Office while meeting with Qatar's emir, Sheikh Tamim bin Hamad Al Thani, that the United States is ready for any scenario in Russia, but, he added, "We continue to urge diplomacy as the best way forward."
The United States has threatened to impose sharp economic sanctions if Russia invades Ukraine. In 2014, Russia annexed Ukraine's Crimean Peninsula, and it says it has no plans to invade Ukraine again.
At the Security Council, Russian Ambassador Vassily Nebenzia tried to use a procedural vote to block Monday's public meeting but narrowly failed to get the requisite support.
He said Russia is not "scared" of discussing the issue, but it just did not understand why a discussion was necessary.
"The deployment of Russian troops within our own territory has frequently occurred on varying scales before and has not caused any hysterics whatsoever," Nebenzia said.
He said that the U.S. and Western colleagues were acting as though an invasion had already taken place, and that they presented no evidence that one was planned.
"Our Western colleagues are talking about the need for de-escalation, but first and foremost, they are whipping up tensions, rhetoric and provoking escalation," he said, calling the discussions about a threat of war "provocative."
All Russian officials have "categorically rejected" plans for an invasion, he said, and anyone who claims the opposite is "misleading you."
Based on its past experiences with Moscow, Ukraine simply cannot accept Russia's declaration, and Moscow should withdraw its troops from near its borders, Ukraine's envoy said.
One of Moscow's main demands fueling the crisis is a guarantee that Ukraine will not join the NATO alliance.
"Ukraine strongly rejects any attempt to use the threat of force as an instrument of pressure to make Ukraine and our partners accept illegitimate demands. There is no room for compromise on principle issues," Ukrainian envoy Sergiy Kyslytsya told the council. "The most principled position for Ukraine is that we have (an) inherent sovereign right to choose our own security arrangements, including treaties of alliance which cannot be questioned by Russia."
He emphasized that Kyiv is prepared to defend itself but supports keeping diplomatic channels with Moscow open. He noted that Ukraine President Volodymyr Zelenskiy has said he is willing to meet with Russian President Vladimir Putin.
"If Russia has any questions to Ukraine, it is better to meet and talk, not to bring troops to Ukraine's borders and intimidate Ukrainian people," the envoy said.
After the meeting, in response to reporters' questions, Kyslytsya said he believes a Russian invasion is "imminent." Asked what he meant by "imminent," he referenced an English-Russian dictionary of diplomacy, reading in Russian.
"Imminent, the first meaning, published in Moscow: approaching, hanging over and only then unavoidable," he said, translating for reporters. "So, we have to work very hard so that the first two stay as it is — the threat is hanging over. It's our duty."
U.S. Pentagon press secretary John Kirby told reporters Monday that "we continue to see, even over the course of the weekend … additional Russian ground forces move in Belarus and around the border with Ukraine," as well as "increasing naval activity in the Mediterranean and Atlantic by Russian fleet vessels." He called the Russian movements "concerning."
NATO has ramped up its military presence in member countries bordering Russia, but NATO Secretary-General Jens Stoltenberg said Sunday that NATO has no intention of sending troops to Ukraine if Russia invades the former Soviet republic.
"We have no plans to deploy NATO combat troops to Ukraine. … We are focusing on providing support," Stoltenberg told the BBC. "There is a difference between being a NATO member and being a strong and highly valued partner as Ukraine."
In the United States, Pentagon spokesperson John Kirby told the "Fox News Sunday” show that a Russian invasion "could happen, really, at any time."
Several countries, including the U.S., have shipped weapons to the Kyiv government to help it defend itself. Ambassador Thomas-Greenfield said the U.S. has given Ukraine more than $5 billion in assistance since 2014 to help it defend itself against Russian aggression.
British Prime Minister Boris Johnson is due to visit the region this week and plans to speak to Putin by phone.
Johnson is considering doubling British troops in the Baltic countries and sending defensive weapons to Estonia, his office said.
VOA's Carla Babb contributed to this report. Some information for this report came from Reuters.