"Negotiations in some ways are still ongoing," he told reporters traveling with him from Washington a day after he discussed Afghanistan with President Donald Trump. Esper declined to talk about his meeting with Trump other than to say it covered a range of issues. He said political decisions are pending.
"I don't want to say anything that gets in front of that or upsets that process," he said. The U.S. envoy to Afghanistan said earlier this week that a deal had been reached in principle to end the war, amid concerns by the Afghan government that American forces will leave too quickly and without requiring the Taliban to reduce violence.
Trump on Wednesday restated his intention to end the conflict prompted by the Sept. 11, 2001, attacks. "We have great warriors there. We have great soldiers, but they are not acting as soldiers, they are acting as policeman, and that's not their job," Trump told reporters at the White House. "So, we would like to get at least a big proportion of them home."
The president added that he'd also like to get "a big portion" of the NATO troops out of Afghanistan. "We're talking with the Taliban. We're talking to the government. We'll see what happens," he said.
Esper said he would discuss Afghanistan over dinner Wednesday in Stuttgart with NATO Secretary-General Jens Stoltenberg to give the alliance's civilian leader "a sense of where I think things are" in the push to close a peace deal.
NATO countries have had troops in Afghanistan through the nearly 18-year conflict, and they have agreed that they would coordinate any final withdrawal. Esper planned to meet with his British counterpart in London on Friday and with his French counterpart in Paris on Saturday. Both countries have played important roles in Afghanistan.
In the in-flight interview, Esper cited "sensitive negotiations" as he declined to talk about specifics, such as the timing of an initial American troop pullout or, more broadly, his level of confidence that the Taliban would live up to their end of any peace agreement.
Among the unanswered questions is whether an agreement with the Taliban will allow for some number of U.S. counterterrorism forces to remain after conventional troops depart. The timing of a Taliban cease-fire also appears in doubt.
"The conflict continues on," he said. "They are conducting attacks. The Afghans are conducting attacks. We're supporting Afghan attacks. That's why we think the best way forward — if we can get the right deal — is a political agreement that leads to a viable outcome."