EXCLUSIVE-U.S. could pull bulk of troops from Syria in matter of days -officials

(Adds details on planning, Esper remarks)

By Phil Stewart and Idrees Ali

WASHINGTON, Oct 13 (Reuters) - The United States is considering plans to withdraw the bulk of American troops from northern Syria in the coming days, two U.S. officials told Reuters on Sunday, in what would be a faster-than-expected timeline for the U.S. pullout amid Turkey's escalating offensive.

U.S. Defense Secretary Mark Esper announced earlier on Sunday that he was acting on orders from President Donald Trump to begin a deliberate withdrawal from northern Syria, where the United States has around 1,000 forces.

Esper did not elaborate on the timing of the withdrawal, saying only that he wanted it to be done "as safely and quickly as possible."

The U.S. officials, who spoke to Reuters on condition of anonymity, said the United States was looking at several options but added it appeared likely the military would pull the majority of its forces in the coming days, instead of weeks.

A full withdrawal could take two weeks or more, although even that could happen faster than expected, one official said.

The disclosure of the fast-paced withdrawal caps off a dramatic week of policy upheaval on Syria, which was once the heart of the Islamic State militant group's so-called caliphate.

It began last Sunday, when Trump decided during a call with Turkey's President Tayyip Erdogan to remove a small number of U.S. forces from northeastern Syria. The decision was lambasted by Trump's critics, who say it opened the door for a Turkish offensive three days later against U.S.-allied Kurdish fighters.

The abrupt U.S. withdrawal from Syria - without any negotiated, diplomatic solution there - is widely viewed as a foreign policy defeat for the United States, which failed to halt an offensive by NATO ally, Turkey, against America's main ally in Syria in war on Islamic State.

The United States says it will not defend the Syrian Kurdish forces from Turkey and Turkish-backed forces, even though the Kurds fought alongside American forces against Islamic State and are guarding prisons holding tens of thousands of the militants.

Esper, speaking in a television interview, said he expected the Syrian Kurds would seek to ensure their survival by turning to America's rivals in Syria's conflict - Russia and Syrian President Bashar al-Assad.

"There's every expectation that the ... Syrian Kurds would cut a deal with the Syrian and Russian forces," he said. (Reporting by Phil Stewart and Idrees Ali Editing by Nick Zieminski)