Biden, Putin hold hour-long talk amid military buildup on Ukrainian border

President Joe Biden and Russian President Vladimir Putin held a talk via phone on Saturday morning amid ongoing and growing tensions over Russia's growing presence at the Ukrainian border. 

The phone call, the first since the leaders spoke to each other late last year, takes place as Russia continues to move large numbers of troops and military equipment to its southwestern border with Ukraine in what appears to be a growing intent to invade the latter country. 

The talk reportedly lasted an hour. Details of the discussion, which Biden conducted from the presidential retreat at Camp David, were not immediately available. 

Warnings from the Biden administration about Russia's potential invasion of Ukraine have ratcheted up in recent weeks. Earlier this week the U.S. State Department warned Americans in Ukraine that they should move to leave the country immediately ahead of Russia's potential invasion of it. 

"U.S. citizens in Ukraine should be aware that the U.S. government will not be able to evacuate U.S. citizens in the event of Russian military action anywhere in Ukraine," the State Department said in a message released Thursday.