"There are objectives that we want to accomplish that condition the withdrawal", Bolton told reporters in Jerusalem, on a trip meant to allay Israeli leaders' concerns about Trump's announcement. "It's not the establishment of an arbitrary point for the withdrawal to take place as President Obama did in the Afghan situation...the timetable flows from the policy decisions that we need to implement".
"We won't be finally pulled out until ISIS is gone", Trump said before departing for Camp David. U.S. officials later said American forces had been given 30 days to leave Syria.
On Dec. 23 - after Defense Secretary Jim Mattis resigned in protest of Trump's withdrawal decision - Trump tweeted that he had discussed what he called a "slow and coordinated (U.S.) pullout" from Syria with Turkish President Recep Tayyip Erdogan. McGurk announced his resignation several days later.
Ziya Meral, director of the London and Beirut-based Centre on Religion and Global Affairs, said it would be "naive" for the U.S. to expect Turkey not to "interfere" in Syria while the YPG remained in control across the border.
Turkey's presidential spokesman called allegations that his country planned to attack the USA -allied Kurds in Syria "irrational" and said Turkey was fighting terrorism for national security.
But Ankara insists that Turkey only targets Daesh and the YPG, which it sees as the offshoot of outlawed Kurdistan Workers' Party (PKK). The latter is undoubtedly a gesture to Netanyahu, who would have to ensure that a pullout of American forces and allies in southern Syria didn't give Iran a foothold from which to launch attacks on Israel.
It must be assured, he added, that any Turkish military actions will not "endanger our troops, but also so that they meet the president's requirement that the Syrian opposition forces that have fought with us are not endangered".
Bolton has urged Kurdish allies not to seek protection from Russian Federation or Syrian President Bashar al-Assad's government.
It was also reported that a Kurdish fighter was killed and another injured.
Fear of a Turkish assault has prompted the Kurds to increase their engagement with the regime of Syrian President Bashar al Assad, who they see as potentially providing them protection from the Turks. But Pentagon officials say about 2 percent of the group's self-proclaimed caliphate remains in the country.
"We will be leaving at a proper pace while at the same time continuing to fight ISIS [Daesh] and doing all else that is prudent and necessary!"
Another option for the Turkish military is to move south inside Iraq and cross the Iraqi-Syrian border to reach areas controlled by Islamic State, the person said.
Netanyahu has pledged to continue to act against Iran in Syria.