Biden considers sending up to 5,000 troops to Eastern Europe as Russia threatens the region with a new war

• The US is weighing sending up to 5,000 troops to Eastern Europe amid fears Russia will invade Ukraine.
• Troops would not be deployed to Ukraine but to NATO-allied countries in the region.

The Biden administration is weighing sending thousands of troops to Eastern Europe, The New York Times first reported, amid concerns that Russia is on the verge of invading Ukraine.

The news came as the State Department ordered the family members of employees at the US Embassy in Kyiv, Ukraine, to leave the country — an ominous development. The department is also permitting nonessential staff to leave, while urging Americans in the country to depart.

Taken together, these moves are indicative of the escalating concerns that a Russian invasion is imminent.

As many as 5,000 troops US troops could be deployed, according to NPR, though it is unclear which countries they would be sent to. Romania, Poland, Hungary, and Bulgaria are being weighed as options, NPR reported.

NATO allies are sending more ships and fighter jets to the region in response to the crisis.

"The United States has also made clear that it is considering increasing its military presence in the eastern part of the Alliance," NATO said in a statement on Monday.

Sending US troops to Eastern Europe would represent the most serious step taken by the Biden administration to date in a bid to deter Russian aggression. The White House has up to this point generally sought to avoid taking steps that may provoke Russia.

The administration has said Russia will face severe economic consequences if it invades Ukraine. But President Joe Biden has said the US will not be obligated to send troops to defend Ukraine in the event of an invasion, given the former Soviet republic is not a NATO member.

Ukraine has sought to join NATO for years and maintains a robust partnership with the alliance. This has drawn Russian President Vladimir Putin's ire, and Kyiv's relationship with NATO is at the center of the recent tensions. The Kremlin has blamed NATO for the crisis, framing the alliance's expanding influence in Eastern Europe as an existential threat. Meanwhile, Russia has gathered tens of thousands of troops on the border of Ukraine.

The Kremlin has said it has no plans to invade, while resisting calls to pull troops from the border to lower the temperature.

As the US and its allies have sought a diplomatic resolution to the hostilities, Moscow has made demands for binding security guarantees — including permanently barring Ukraine from NATO. But the alliance and the US have made it clear that NATO's open-door policy is nonnegotiable.

Europe hasn't faced a crisis on this scale since the Cold War as concerns mount that Russian forces can further break apart a sovereign country or even seize all of it. It's among the toughest foreign-policy tests any US president has encountered in years, and it's hardly the first time Russia has exhibited aggression toward Ukraine.

In 2014, Russia invaded and annexed Crimea from Ukraine. And since that year, the Kremlin has backed rebels in a war against Ukrainian forces in the eastern Donbass region. Experts say Putin views Ukraine as unfinished business and wants to rid it of Western influence.

The UK foreign office on Saturday said it had information that Russia was planning to "install a pro-Russian leader in Kyiv as it considers whether to invade and occupy Ukraine." Russia's Ministry of Foreign Affairs denied the accusation in a tweet on Saturday.

Biden is set to hold a secure video call with European leaders on Monday afternoon to discuss Russia's military buildup on Ukraine's borders.