WASHINGTON - The Trump administration has started returning US troops home from Syria after claiming a victory in the fight against the Islamic State (IS), the White House said on Wednesday.

"We have started returning United States troops home as we transition to the next phase of this campaign," said White House Spokesperson Sarah Sanders in a statement, claiming that America has "defeated the territorial caliphate".

All US State Department personnel are being evacuated from Syria within 24 hours, reported Reuters after the White House announcement, citing an anonymous administration official.

The official also revealed that the time-frame for the troops withdrawal from the war-torn Arab country is expected to be between 60 and 100 days.

Sanders' statement came about one hour after US President Donald Trump hinted in a tweet about imminent US troop withdrawal from Syria.

"We have defeated ISIS (the IS) in Syria, my only reason for being there during the Trump Presidency," Trump tweeted on Wednesday morning.

Earlier on the day, US media cited anonymous officials as saying that the United States is planning a "rapid" and "full" withdrawal of troops from Syria.

Trump has long voiced his desire to bring the US troops back home when possible, while senior administration officials including Defense Secretary James Mattis have advocated for a longer-term military deployment in Syria to secure a victory against the IS.

Currently, there are more than 2,000 US soldiers deployed in Syria.