MUNICH — Acting U.S. defense chief Patrick Shanahan on Friday called on allies to expand efforts against the Islamic State globally, even as the U.S. plans to withdraw its troops from Syria.

“While the time for U.S. troops on the ground in northeast Syria winds down, the United States remains committed to our coalition’s cause, the permanent defeat of ISIS, both in the Middle East and beyond,” Shanahan said Friday at the 2019 Munich Security Conference.

Shanahan met with German Defense Minister Ursula von der Leyen and other foreign leaders on plans to defeat the Islamic State group.

Shanahan’s comments come as the top U.S. commander for the Middle East, Gen. Joseph Votel, told CNN that he would not have advised President Donald Trump to withdraw the 2,000 U.S. forces currently in Syria. Trump’s announcement of a withdrawal led to the resignation of Defense Secretary Jim Mattis in December.

“It would not have been my military advice at that particular time ... I would not have made that suggestion, frankly,” Votel told CNN of the troop withdrawal. The caliphate “still has leaders, still has fighters, it still has facilitators, it still has resources, so our continued military pressure is necessary to continue to go after that network."

The U.S. has been meeting with allies to discuss what type of additional forces they could provide to help monitor Syria after a U.S. withdrawal, particularly in northeast Syria, to keep Syrian Democratic Forces that have been key to the fight from being attacked by Turkey or pro-government forces after a withdrawal, Shanahan told reporters traveling with him this week.

Pentagon officials have warned the Islamic State has morphed into a global ideological network as it’s lost its grip on a physical caliphate. Shanahan said he was working with allies to develop ways to permanently defeat "ISIS’s influence across the globe.”

“I, for one, envision an even bigger and stronger coalition going forward – one that has evolved to meet the global threat posed by ISIS’s offshoots and its murderous ideology; a coalition that is utilizing the most effective collective capabilities to thwart ISIS’s malign influence and activities in places like Afghanistan, the Philippines, the Sahel, the Sulu Sea, and beyond,” he said.

Von der Leyen signaled she was in alignment with Shanahan’s assessment on the Islamic State as an evolved threat, saying that while the “physical caliphate,” is destroyed, "we are seeing the Islamic State change its face, go underground and build new networks.”

She also stressed the need for Iraq reconstruction, where Germany has had a role. The goal, she said, must be to support the Iraqi government in ensuring all groups in the country are adequately represented.

In Syria, she said, the multibillion-dollar reconstruction effort requires a political settlement first and for refugees to be resettled.

U.S. officials say the Islamic State is holding on to fewer than two square miles in Syria, or less than two square miles, in the villages of the Middle Euphrates River Valley, where the bulk of the fighters are concentrated.

On Capitol Hill in recent days, senior Defense Department officials have affirmed progress against ISIS but repeatedly warned that too rapid a withdrawal could create instability in the region. Votel said in congressional testimony that he was not consulted or warned Trump would declare a U.S. troop withdrawal and that the group still had “tens of thousands” of followers.

In the U.S., Trump’s withdrawal plans have attracted and alienated lawmakers from both parties, highlighted when the Senate, in a bipartisan vote Feb. 5, urged Trump not to precipitously withdraw troops from Syria and Afghanistan.