President Joe Biden is considering deploying several thousand U.S. troops, as well as warships and aircraft, to NATO allies in the Baltics and Eastern Europe, an expansion of American military involvement amid mounting fears of a Russian incursion into Ukraine, according to administration officials.

The move would signal a major pivot for the Biden administration, which up until recently was taking a restrained stance on Ukraine, out of fear of provoking Russia into invading. But as Russian President Vladimir Putin has ramped up his threatening actions toward Ukraine, and talks between American and Russian officials have failed to discourage him, the administration is now moving away from its do-not-provoke strategy.

In a meeting Saturday at Camp David, the presidential retreat in Maryland, senior Pentagon officials presented Biden with several options that would shift American military assets much closer to Putin’s doorstep, the administration officials said. The options include sending 1,000 to 5,000 troops to Eastern European countries, with the potential to increase that number tenfold if things deteriorate.