The US has accused Russia of an “act of aggression” over its alleged deployment of soldiers in Ukraine’s Crimean peninsula, BBC reports.
President Barak Obama said Russian President Vladimir Putin’s assertion that no troops had been mobilised was “not fooling anyone”, and that Russia had no right to intervene in Crimea.
Secretary of State John Kerry, visiting Kiev, has praised the “restraint” of the new government.
Moscow is now in de facto control of Crimea, where tensions are high.
Troops in what appear to be Russian uniforms surround Ukrainian military bases and other installations, while two Ukrainian warships are reported to be blocked by a Russian ship in the port of Sevastopol.
Earlier, Putin said Ukraine was in “chaos” having been seized by “nationalists” and “anti-Semites”, and that Russia had a right to protect Russian citizens in the country.
But Obama said Russia had violated international law and was not “fooling anybody”.
The sight of Russian troops out of their barracks in Crimea was not an indication of concern for Russian nationals, he said, “but is based on Russia seeking through force to exert influence on a neighbouring country.
“That is not how international law is supposed to operate.”
In Kiev, Kerry also dismissed Putin’s denial of troop deployments.
“I think that it is clear that Russia has been working hard to create a pretext for being able to invade further. Russia has talked about Russian-speaking minority citizens who are under siege… They’re not,” he said.
“It is not appropriate to invade a country and dictate what you want to achieve at the end of the barrel of a gun,” he said, saying it was “not 21st Century behaviour.”
Kerry praised the post-uprising government, saying they had “acted remarkably responsibly by urging total calm, by not wanting to have any provocation”.
He was speaking after holding talks with interim President Olexander Turchynov, Prime Minister Arseniy Yatsenyuk and other new government figures.
The general secretary of Nato, Anders Fogh Rasmussen, has said Russia “continues to violate Ukraine’s sovereignty and territorial integrity, and continues to violate its international commitments,” despite the international condemnation.
“These developments present serious implications for the security and stability of the Euro-Atlantic area” he said, saying that Nato allies “stand together in the spirit of strong solidarity in this grave crisis”.
Nato and Russia – which is not a member – are scheduled to hold talks on Wednesday.