Kabul, Oct. 22 -- The U.S. may leave some forces in Syria to secure oil fields and make sure they don't fall into the hands of a resurgent Islamic State, Defense Secretary Mark Esper said Monday, even though President Donald Trump has insisted he is pulling troops out of the country and getting out of "endless wars."

The Pentagon chief said the plan was still in the discussion phase and had not yet been presented to Trump, who has repeatedly said the Islamic State has been defeated.

Esper emphasized that the proposal to leave a small number of troops in eastern Syria was intended to give the president "maneuver room" and wasn't final.

"There has been a discussion about possibly doing it," Esper told a press conference in Afghanistan be...