Biden presented with options to bolster NATO with U.S. troops amid rising tensions over Ukraine

Defense Department officials on Saturday presented President Biden with options to send "several thousand" troops to Eastern Europe to bolster NATO allies, a Pentagon official told CBS News. 

The proposed plans come as Russia continues to build up forces near Ukraine's border, with no sign of de-escalation. Mr. Biden in December ruled out sending U.S. troops to Ukraine if Russia invades, but his administration has been open to reenforcing NATO allies on the eastern flank. 

Those troops could come from U.S. forces already stationed in Europe or from the United States. As of Sunday night, no units had been given orders to move.