Moscow: Russia has the right to "protect its interests and Russian-speaking populations" in Ukraine, President Vladimir Putin has told his US counterpart Barack Obama.
Putin told Obama there was a "real threat weighing on the lives and the health of Russian citizens" in Ukraine, according to a Kremlin statement.
The Russian president accused the new government in Kiev of supporting "criminal actions by ultranationalists", the Kremlin said.
The two leaders spoke yesterday by telephone after Russia`s parliament authorised military action in Ukraine in a dramatic escalation of tensions.
The Kremlin statement said the conversation was instigated by the US side and focused on the "extraordinary situation in Kiev".
It came after Obama`s national security team met yesterday to weigh policy options as Washington tried to keep pace with the fast escalating crisis in Ukraine and Crimea.