The UN Security Council's emergency talks that took place at the request of Russia hours before Ukraine begins a "large-scale anti-terrorist operation", failed to yield any tangible outcome as Moscow and the western powers traded accusations against each other for the crisis.
The special session began after UN assistant secretary-general Oscar Fernandez-Taranco opened the talks saying Ukraine "teeters on the brink" threatening to snowball into a larger international crisis.
"Russia, which shares a large border with Ukraine, as well as the broader European region, faces spillover effect of potentially severe consequences. Such scenarios will also have repercussions for the entire international community."
The UN session took place as Ukraine had given an ultimatum (0600 GMT) to the pro-Russian protesters in the eastern cities to lay down arms or face military action. Russia warned that Kiev's military action would have serious repercussions.
Britain's UN ambassador Mark Lyall Grant told the gathering that Moscow has been amassing thousands of troops on Ukraine's borders potentially gearing up for military intervention.
"Satellite images show that there are between 35,000 and 40,000 Russian troops in the vicinity of the border with Ukraine equipped with combat aircraft, tanks, artillery and logistical support units. This is in addition to the 25,000 Russia troops based illegally in Crimea."
Russian ambassador to the UN Vitaly Churkin put the blame squarely on the west and said it was the responsibility of the western powers to "avert a civil war".
"A very dangerous situation has taken shape. A further escalation of it must be prevented without delay.... It is precisely on the West that the possibility to avert a civil war in Ukraine is depending now."
Ukraine's UN ambassador Yuriy Sergeyev vowed that a "Crimea scenario" would not be repeated in Ukraine's eastern cities and said they would press ahead with the military measures if the separatists do not give up their arms.
"We demand to leave us in peace. It's really the final warning cry."
US ambassador to the UN Samantha Power accused Moscow of orchestrating the latest events in Ukraine putting the lives of scores of civilians at risk.
"The human stakes of what is happening in Ukraine are extremely high. The lives of innocent civilians are at risk yet we are being bombarded by Russian disinformation and propaganda, while the Ukrainians are being confronted by incitement and violence. This instability was written and choreographed in and by Russia."
European Union foreign ministers are also meeting later in the day in Luxembourg to address the Ukraine crisis.