The United States has 900 troops in Syria, and 2,500 more in neighboring Iraq, on a mission to advise and assist local forces trying to prevent a resurgence of Islamic State, which in 2014 seized large swathes of both countries but was later defeated.
There is growing concern that the Israel-Hamas conflict could spread through the Middle East and turn U.S. troops at isolated bases into targets.
Earlier on Wednesday, a U.S. MQ-9 drone was shot down near Yemen by the Iran-aligned Houthi movement over the Red Sea.
Officials said the drone was believed to be in international waters when it was shot down.
The United States has sent warships and fighter aircraft to the region since the Israel-Hamas conflict erupted on Oct. 7, including two aircraft carriers, to try to deter Iran and Iran-backed groups. The number of troops added to the region is in the thousands.