US ambassador to the United Nations Linda Thomas-Greenfield warns that "the consequences of Russia's actions will be dire, across Ukraine, across Europe, and across the globe."
The Kremlin's carefully staged move flies in the face of European efforts for a diplomatic solution to the escalating crisis in Ukraine.
Leaders of the separatist regions released televised statements earlier Monday pleading with Putin to recognize them as independent states and sign friendship treaties.
"The embassy is preparing for all sorts of scenarios, but as of today, we are staying here in Ukraine, because our presence here is necessary for Israelis who are staying here in Ukraine," Ambassador Michael Brodsky says.
American and Russian presidents agree "in principle" to a proposal by France's Emanuel Macron for one last effort to stave off what the British PM warned would be "the biggest war in Europe since 1945." Satellite images show Russian field deployments near the border with Ukraine; US Embassy in Moscow tells Americans to "have an evacuation plan."
The palace says the 95-year-old British monarch will continue with light duties at Windsor Castle over the coming week.
Israel readies for emergency intake of thousands of potential Ukrainian immigrants fleeing a war. Western powers prepare "robust and comprehensive" sanctions against Moscow in case it invades Ukraine.
Activities include campus demonstrations, rallies and lectures with pro-Palestinian activists erecting mock checkpoints and walls.
Washington issues some of its starkest, most detailed warnings yet about how a Russian invasion of Ukraine might unfold.
Russia reportedly adds 7,000 troops near Ukraine border as Ukrainian military and Moscow-backed rebels trade accusations of shelling across ceasefire line.