The base is located in Tel Baidar in the eastern Syrian province of Hasaka, Beirut-based Al Mayadeen reported.
The United States has set up 24 military bases and four outposts in Syria despite protests from the Syrian government. The facilities have been increasingly targeted by militias in the past weeks that Washington says are affiliated with Iran. Tehran has rejected the accusations.
However, since October, the US has carried out a series of "self-defense" strikes in Syria in response to the alleged attacks on US personnel in Iraq and Syria by pro-Iran militia groups.