The Defense Department is exploring its options to completely withdraw all U.S. troops deployed in Afghanistan, in the event President Donald Trump abruptly makes the decision, according to NBC News.

The ongoing planning, which was not explicitly directed by the White House, includes procedures for a completely withdrawal of U.S. forces within weeks, current and former officials reportedly said.

The Defense Department's move comes in the wake of Trump's decision to withdraw the majority of U.S. troops in Syria, as Turkish-backed forces embark on a campaign against Kurdish groups near the Syria-Turkey northeast border.

An official described the planning as “prudent,” while another official called the recent actions in Syria as a potential “dress rehearsal” for Afghanistan, NBC News reported.

Trump initially recalled roughly two dozen service members in the immediate vicinity of the Turkish excursion into Syria, but later expanded that order to around 1,000 US troops in northern Syria. Defense Secretary Mark Esper on Monday said that an undetermined, small number of U.S. troops could still be stationed in northeast Syria to secure oil fields and prevent ISIS from taking control.

The president has long cited his campaign promise to reduced the U.S. presence in the Middle East, and to limit the country's involvement in “endless wars.”

“USA soldiers are not in combat or ceasefire zones,” Trump said in a now-deleted tweet on Sunday. “We have secured the Oil. Bringing soldiers home!”

Trump's decision to withdraw U.S. forces caught numerous military officials and lawmakers by surprise, and attracted bipartisan condemnation for what they characterized as an abandonment of U.S. allies and principles. Roughly 11,000 Kurds — who were allied with the U.S. in the region — were killed in the fight against ISIS, and many more were relied upon by the U.S. to evict the extremists from their strongholds.

“This impulsive decision by the president has undone all the gains we've made, thrown the region into further chaos, Iran is licking their chops, and if I'm an ISIS fighter, I've got a second lease on life,” Sen. Lindsey Graham said during a Fox News interview on October 7. (On Sunday, in an about-face, Graham told Fox News he is “increasingly optimistic this could turn out very well.”)

Former U.S. Central Command commander and retired Army Gen. Joseph Votel also condemned the withdrawal, and reflected on the U.S.'s reliance on the Kurds.

“Without it, President Donald Trump could not have declared the complete defeat of ISIS,” Votel wrote of the Kurdish help against ISIS in Syria. Trump has frequently claimed ISIS has been unequivocally defeated.

The U.S. has pulled out 2,000 troops from Afghanistan so far this year, bringing the total number of forces in the country to around 13,000, Task & Purpose reported. Earlier in October, Esper said he was confident the U.S. military could withdraw thousands more troops without adversely affecting operations.

    Esper, who visited Afghanistan on Monday, advised not to compare U.S. policy for Syria with that of Afghanistan.

    “Very different situations, very different adversaries if you will, very different level of commitment,” he said, according to NBC News. “Very clear policy direction on one.

    “All these things should reassure Afghan allies and others they should not misinterpret our actions in the region in the recent week or so in regard to Syria and contrast that with Afghanistan,” Esper added.

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