WASHINGTON (Reuters) – U.S. President Donald Trump wants combat forces reduced in Afghanistan by the next U.S. presidential election, Secretary of State Mike Pompeo said on Monday, introducing a timeline to Washington's plan of cutting troop numbers there.

Trump's South Asia strategy, unveiled in August 2017, called for an open-ended deployment of U.S. forces with the goal of compelling the Taliban to negotiate peace with the Kabul government to end nearly 18 years of war.

“That's my directive from the president of the United States,” Pompeo told The Economic Club of Washington D.C. when asked whether he expects the U.S. to reduce troops in Afghanistan before the next election in November 2020.

“He's been unambiguous: end the endless wars, draw down, reduce. It won't just be us,” he said, referring to Trump's directive. “We hope that overall the need for combat forces in the region is reduced.”

He joked that delivering on the president's goal would be “job enhancing” for him.

The disclosure of a timeline will add to speculation that Trump is prepared to strike any deal with the Taliban insurgency that will allow for at least partial U.S. withdrawal before American voters go to the polls, irrespective of concerns by the U.S.-backed government in Kabul.

Pompeo's comments also come at a delicate moment, as the United States prepares to engage in another round talks with the insurgents. Disclosing Trump's goals of withdrawing forces could weaken the U.S. negotiating position if the Taliban believe Trump wants to withdraw, irrespective of the outlines of the deal.

On Friday, the State Department said Pompeo and Afghan President Ashraf Ghani agreed in a phone call to “accelerate efforts” to end the war, and that the United States remained committed to a conditions-based drawdown of troops.

Pompeo said he was optimistic about negotiations with the Taliban to end the nearly 18-year-old war in Afghanistan.

Washington wants to negotiate a deal under which foreign forces would pull out of Afghanistan in return for security guarantees by the Taliban, including a pledge that the country will not become a safe haven for terror groups.

“We want them to take their country back, and we want to reduce what is, for us, tens of billions of dollars a year in expenditures,” Pompeo added.

The U.S. and other NATO troops are stationed in Afghanistan as part of a mission to train, assist and advise Afghan forces and to carry out counterterrorism operations.

(Additional reporting by Phil Stewart. Editing by Jonathan Oatis)