Linda Thomas-Greenfield said she asked Secretary of State Antony Blinken to attend the Council meeting on Ukraine on “to signal our intense commitment to diplomacy.”
“Our goal is to convey the gravity of the situation. The evidence on the ground is that Russia is moving toward an imminent invasion. This is a crucial moment,” she tweeted.
Blinken, on his way to a security conference in Munich later this week, would appear at the UN to “to offer and emphasize the path toward de-escalation, and to make it clear to the world that we are doing everything we can to prevent war,” she continued.
Russia has repeatedly denied it is planning an invasion of Ukraine.
But the US says Moscow has continued building up its forces and combat readiness along the border with its Eastern European neighbor, despite the Kremlin saying it was pulling back troops.
A senior State Department official said the US had watched with growing alarm as Russia claimed to be de-escalating Wednesday, but in fact appeared to be escalating.
The official, who spoke on condition of anonymity, said the situation bore a resemblance to the phase that preceded Moscow’s incursion into Georgia in 2008.
The official also said the US was concerned by the recent shelling in the Donbass region of eastern Ukraine and cited what Washington says are preparations to fabricate a pretext for invasion, an accusation echoed by NATO.
Russian media published articles and photographs this week of purported secret mass graves in Donbass, controlled by Moscow-aligned secessionists who have been battling Ukrainian government forces since 2014.
Earlier this week Russian leader Vladimir Putin claimed Kyiv was committing “genocide” there.
After reports of shelling on the frontline in Donbass, US Defense Secretary Lloyd Austin warned again in Brussels that Russia could be seeking an excuse to invade.
“We’ve said for some time that the Russians might do something like this in order to justify a military conflict. So we’ll be watching this very closely,” Austin told journalists after a meeting with NATO defense ministers.
This is could be the “most perilous moment” for peace and security since the end of the Cold War, the senior State Department official said.