By Michael Hernandez

WASHINGTON

 U.S. President Donald Trump said Wednesday the U.S.-led coalition has succeeded in militarily defeating the Daesh terrorist group, signaling a looming withdraw of forces from Syria.

"We have defeated ISIS in Syria, my only reason for being there during the Trump Presidency," Trump said on Twitter using another name for Daesh. 

The announcement follows reports the U.S. is preparing to withdraw its roughly 2,000 troops from northeastern Syria. 

Trump had previously voiced his intent to leave Syria, but faced pushback from the Pentagon's top brass and some of his top officials who had sought to maintain the U.S.'s military posture in the country until Iranian forces exited. 

The White House appeared to confirm the U.S. departure, stressing military victories against Daesh in Syria "do not signal the end of the Global Coalition or its campaign.

"We have started returning United States troops home as we transition to the next steps of this campaign," spokeswoman Sarah Sanders said. "The United States and our allies stand ready to re-engage at all levels to defend American interests whenever necessary."

But the statement leaves unclear the extent of the withdrawal, as well as its timeline. Reports suggested all State Department personnel would depart Syria within the next 24 hours while U.S. forces would leave within 60 to 100 days. 

The National Security Council did not comment on the reported timeline when asked about the matter by Anadolu Agency. 

The reassurances presented by the White House were met with stiff opposition from some on Capitol Hill who warn far more work remains against Daesh. 

Senator Lindsey Graham, a close ally of the president, said doing so "would be a huge Obama-like mistake," a likely reference to the removal of U.S. forces from Iraq under former President Barack Obama. 

"With all due respect, ISIS is not defeated in Syria, Iraq," Graham said in a series of twitter posts. "President @realDonaldTrump is right to want to contain Iranian expansion. However, withdrawal of our forces in Syria mightily undercuts that effort and put our allies, the Kurds at risk."

"A decision to withdraw will also be viewed as a boost to ISIS desire to come back," he said. 

Trump's decision is a "grave error that is going to have incredible consequences that potentially have not been fully thought through," said Republican Senator Marco Rubio in a Facebook Live video, echoing Graham's sentiment.

The decision follows a military operation in northeastern Syria vowed by Turkish President Recep Tayyip Erdogan against the YPG/PKK. Ankara has carried out two separate military operations in northern Syria in the past. 

Trump made the decision following a phone call with Erdogan last Friday, according to TRT World, Turkey's English-language state broadcaster. 

The U.S. had warned publicly against a new operation in northeastern Syria as it works alongside the YPG-led SDF, which is fighting Daesh in its last remaining major foothold in eastern Syria. 

The Pentagon said in a statement that while it has begun the process of removing forces from Syria, "we will continue working with our partners and allies to defeat ISIS wherever it operates."

*Kasim Ileri contributed to this report