Donald Trump, President of the United States of America, and Recep Tayyip Erdogan, President of Turkey, during the NATO Summit last July. Bernd von Jutrczenka | picture alliance | Getty ImagesPresident Donald Trump on Sunday defended his decision to pull back U.S. troops from Syria to clear the way for Turkish forces, despite mounting bipartisan criticism that the withdrawal abandons Kurdish allies in the region and empowers the remnants of the so-called Islamic State.The U.S. is evacuating 1,000 U.S. troops from the region “as safely and quickly as possible” in the face of Turkey’s rapid military advance against the Kurds, Defense Secretary Mark Esper told CBS’ “Face the Nation” Sunday. Esper said the troops would not leave Syria completely. Trump defended the withdrawal, saying “endless wars must end.” It was “very smart” not to be involved in the fighting along the Turkish border, he added, and if other powers want to intervene in the conflict, “Let them!” “Those that mistakenly got us into the Middle East Wars are still pushing to fight,” Trump wrote on Twitter. “They have no idea what a bad decision they have made. Why are they not asking for a Declaration of War?”The president said he was working with Republicans and Democrats in Congress to possibly impose sanctions on Turkey for its invasion. Trump signed an executive order Friday giving his administration broad authority to sanction Turkey. “We’ll be taking in new information and we’re ready to go at a moment’s notice to put on sanctions,” Treasury Secretary Steve Mnuchin said. “Now we have warned the Turks…They know what we will do if they don’t stop these activities.”Defense Secretary Esper told Fox News that he was aware of reports of ISIS prisoners escaping due to the Turkish invasion, as well as atrocities reportedly being committed against Syrian Kurds by members of a Turkish-supported Syrian Arab militia.Esper said that Turkey was ready to invade the country to attack Kurdish forces regardless of U.S. actions, and there was “no way” U.S. forces could have stopped the them.James Mattis, Trump’s first defense secretary, warned that a premature withdrawal would lead to a resurgence of ISIS after years of U.S. and Kurdish efforts to destroy the group. Mattis resigned as defense secretary last year over disagreements with Trump’s foreign policy, including the president’s desire to pull troops out of Syria.”We may want a war over; we may even declare it over. You can pull your troops out as President Obama learned the hard way out of Iraq, but the ‘enemy gets the vote,’ we say in the military. And in this case, if we don’t keep the pressure on, then ISIS will resurge. It’s absolutely a given that they will come back,” Mattis said in an interview with NBC’s “Meet The Press.”Trump’s decision has also sparked widespread opposition from his own party, including close allies such as Sen. Lindsey Graham. The senator from South Carolina has called on the president to change course.Esper said he spoke to Trump on Saturday night amid growing signs that the Turkish invasion was becoming more dangerous.”In the last 24 hours, we learned that they likely intend to expand their attack further south than originally planned — and to the west,” Esper said.U.S. allies and aid organizations have pushed for an end to the Turkish invasion, which has surfaced fears of a new humanitarian crisis in the region and a resurgent ISIS threat. France and Germany suspended arms sales to Turkey on Saturday in response to the invasion.Over 130,000 people have been displaced from rural areas around the northeast Syrian border towns of Tel Abyad and Ras al Ain due to the conflict, according to the United Nations.