KABUL, Afghanistan — The U.S. is considering what cuts to U.S. force levels could support peace negotiations in Afghanistan while balancing risk there, Acting Defense Secretary Patrick Shanahan said Sunday.

Shanahan made the surprise visit, his first since becoming acting defense secretary, to meet with U.S. and Afghan leaders to discuss the nascent peace talks and assess the risks tied to a potential drawdown. Shanahan was named acting secretary in December by President Donald Trump to replace former Defense Secretary Jim Mattis, who resigned.

Shanahan’s visit comes days after the top U.S. negotiator for peace talks with the Taliban, Special Representative for Afghanistan Reconciliation Ambassador Zalmay Khalilzad, announced that the two parties have agreed in principle to framework where the Taliban would agree to prevent any terror groups from operating under their control, and the U.S. would begin a draw down of forces.

"It always gets back to assurances," Shanahan said. "There's risk-taking but there have to be assurances. and putting in place the mechanisms to get people the confidence to take the risk," Shanahan said.

However, the Taliban have not agreed to meet with the Afghan government, which is a necessary component of a final peace deal.

Shanahan said he would take information gathered during his time in Kabul to NATO, where he is expected at a defense ministerial later this week, and back to the White House. Trump has previously pressed for a withdrawal of forces, who have been fighting in Afghanistan since 2001.

“I think the U.S. military has strong security interests in the region. It’s presence will evolve out of those discussions,” Shanahan said. “We are going to leave it to the teams to start to look at what mix, combination makes the most sense.”

In December, multiple news outlets reported that the White House was considering withdrawing as many as 7,000 of the 14,000 U.S. troops now in Afghanistan; and last week the Taliban said that as part of the negotiations with Khalilzad those forces would be withdrawn by May.

Shanahan said that's not the case.

“I have not been directed to step down our forces in Afghanistan,” Shanahan said.