"Our forces will stay on in very limited numbers in northeast and At Tanf to continue our clearing operations and stability operations against ISIS[Daesh] for a period of time not to be determined at this point", Jeffrey told reporters.
Last week, US President Donald Trump confirmed that a total of 400 US troops will remain in Syria.
White House spokesperson Sarah Huckabee Sanders told reporters on Friday that the territorial caliphate of the Daesh terror group has been completely eliminated in Syria.
Trump announced in December that he had decided to pull out troops from Syria promising to bring about 2,000 US servicemen back home. However, no exact deadline for the return of troops has been revealed by US officials yet.
United States and its allies have been conducting operations against the Islamic State in Syria and neighboring Iraq since 2014. The US-led coalition's actions in Syria have never been authorized by either Damascus or the UN Security Council.
*Daesh (also known as Islamic State, IS, ISIS, ISIL) a terrorist group banned Russia and man other countries.