No US withdrawal from Syria until IS destroyed: Bolton

Washington:White House National Security Adviser John Bolton has contradicted President Donald Trump's decision to immediately withdraw troops from Syria, laying out conditions for a pullout that can leave US forces there for months or even years.

Speaking during a visit to Israel on Sunday, Bolton said that American forces would remain in Syria until the last remnants of the Islamic State were defeated and Turkey provided guarantees that it would not strike Kurdish forces allied with the US.

He and other top White House advisers led a behind-the-scenes effort to slow the President's order and reassure allies, including Israel, the New York Times reported.

"We don't think the Turks ought to undertake military action that's not fully coordinated with and agreed to by the US, at a minimum so they don't endanger our troops," Bolton said in Jerusalem, ahead of a visit on Tuesday to Turkey.

He also acknowledged that pockets of the Islamic State remained undefeated and that a quick US pullout could endanger US partners and allies in the region, as well as American forces themselves.

Trump, who had earlier declared the battle won against the militants and refused military entreaties for more time, said on Sunday that he remained committed to the withdrawal but told reporters: "I never said we're doing it that quickly."

Among the policy decisions still to be made was what to do about the tens of thousands of Syrian Kurdish fighters that US forces had trained, armed and advised to carry out the ground war against the Islamic State.

Turkey, a NATO ally, considers them terrorists and has vowed to drive them out of the northeastern Syrian territory seized from the militants as soon as the Americans leave.

Trump's troop withdrawal announcement in December shocked allies and administration officials alike, with Defence Secretary Jim Mattis and senior aide Brett McGurk resigning soon after.

On Saturday, Pentagon Chief of Staff Kevin Sweeney became the third senior official to announce his resignation.

Bolton said there was no timetable for the US withdrawal from Syria but that there was not an unlimited commitment. He also said Trump wanted to ensure that the Islamic State was "destroyed".

On Tuesday, US Secretary of State Mike Pompeo will begin a week-long tour of the Middle East designed to reassure allies in the region.

Plans and assurances offered by Bolton in Israel were additional confirmation that withdrawal plans were on hold until conditions on the ground matched the President's stated assessment of the situation in Syria.

The US partnership with the Kurdish-led Syria Democratic Forces (SDF) was credited with playing a major role in the demise of Islamic State. But the main fighting force in the SDF is the Kurdish YPG militia, which Turkey regards as a terrorist group.

On Sunday, a spokesman for Turkish President Recep Tayyip Erdogan said it was "irrational" to suggest Turkey targeted Kurds.