Trump said that otherwise US troops are "moving out nicely."

President Donald Trump said Monday a small number of US troops remain in Syria, some near the border with Jordan and others deployed to secure oil fields.

Trump's comments followed a US pullout from northeastern Syria, leaving the Kurds, America's staunchest allies in the fight against Islamic State, to face invading Turkish forces.

Speaking at a cabinet meeting, Trump said the "small number" of US troops staying behind were in an entirely different part of Syria, near its border with Jordan and Israel.

He said another group still in Syria "secured the oil," a reference to oil fields that the US hopes to keep from falling into the hands of jihadist fighters.

"I always said if you're going in, keep the oil," Trump said, suggesting that the US would "maybe get one of our big oil companies in to do it properly."

Trump said that otherwise US troops are "moving out nicely."

US Defense Secretary Mark Esper said earlier in Kabul, however, that the US withdrawal would take "weeks not days."

"We have troops in towns in northeast Syria that are located next to the oil fields. The troops in those towns are not in the present phase of withdrawal," Esper said.