Watch Live: Defense Secretary and Chairman of the Joint Chiefs hold briefing amid Russia-Ukraine crisis

Defense Secretary Lloyd Austin and Chairman of the Joint Chiefs of Staff General Mark Milley are briefing reporters at the Pentagon on Friday amid Russia's military buildup near Ukraine's border. 

For the past several months, Russia has been building forces in the western parts of Russia near Ukraine and in Belarus, north of Ukraine. The U.S. along with its NATO allies has called on Russia to deescalate the tensions and warned of consequences if Russia launches another incursion.

There are no plans to send U.S. troops to Ukraine, but the U.S. has put 8,500 U.S. troops from stateside bases on heightened alert to potentially deploy to Eastern Europe. The vast majority of those 8,500 troops would support the NATO Response Force if activated by the alliance.