WASHINGTON, Dec. 22 (Xinhua) -- Brett McGurk, the U.S. envoy for the global coalition to defeat Islamic State (IS), resigned on Friday, according to media reports.

McGurk's resignation has been confirmed and would be effective from Dec. 31, media reports cited a U.S. State Department official as saying.

Similar to U.S. Defense Secretary James Mattis' resignation on Thursday, McGurk's departure was another sign of senior official's objection over the White House's decision to withdraw U.S. troops from Syria.

The Trump administration announced Wednesday that it has started returning U.S. troops home from Syria after claiming a victory in the fight against the Islamic State, declining to provide more details on the exit timetable.

Earlier this month, McGurk said that it would be unwise to withdraw U.S. troops from fighting against IS, "even as the end of the physical caliphate is clearly now coming into sight, the end of ISIS (IS) will be a much more long-term initiative."

The United States has deployed troops to Syria fighting against the IS since 2015, and there are more than 2,000 U.S. soldiers in Syria currently.