• Turkey will not be permitted to kill Kurdish fighters in northern Syria, and a U.S. withdrawal from the country won't happen without a deal to protect them, White House national security advisor John Bolton told reporters on Sunday.
  • Bolton described the stipulation as President Donald Trump's position, responding to numerous questions over Washington's support for its Kurdish partners in the wake of the president's surprise announcement on December 19 to pull the roughly 2,000 deployed U.S. troops from Syria.   
National Security Advisor John Bolton speaks to reporters as he announces that the U.S. will pull out of a treaty with Iran during a news conference in the White House briefing room in Washington, October 3, 2018.

The U.S.'s planned drawdown of troops in Syria will be conditioned upon an agreement with Turkey that protects Kurdish fighters in the region who have been pivotal to battling ISIS, White House national security advisor John Bolton said on Sunday.

Speaking to reporters in Jerusalem during a visit to Israel and Turkey, intended in part to reassure allies amid criticism over the White House's Syria decision, Bolton fielded numerous questions about Washington's support for its Kurdish partners, and the U.S.'s plans to reduce its footprint in the strife-torn country. He described the stipulation as President Donald Trump's official position.

The Kurds have been steadfast local allies in the fight to repel Islamic State (IS) in Syria. Trump's surprise decision last month to pull 2,000 U.S. troops from the country unsettled America's partners, leaving the Kurds especially vulnerable to Turkish attack or a takeover by the regime of Syrian President Bashar al Assad.

"We don't think the Turks ought to undertake military action that's not fully coordinated with and agreed to by the United States at a minimum, so they don't endanger our troops," Bolton said on Sunday. In addition, Turkey must "meet the president's requirement that the Syrian opposition forces that have fought with us are not endangered."

Bolton added that Trump is fully committed to the fight against terror, and as such "wants the ISIS caliphate destroyed." On Monday, the White House's top national security official is expected to travel to Turkey for talks with Turkish officials about their aims and capabilities in combating IS.

A Kurdish fighter from the People's Protection Units (YPG) looks at a smoke after an coalition airstrike in Raqqa, Syria June 16, 2017.

The president has touted complete victory over ISIS, the primary reason behind the U.S.'s troop presence in Syria, and its support for Kurdish militia fighters known as the Kurdish People's Protection Units, or YPG.

However, Trump's decision to reduce forces in Afghanistan and Syria were deciding factors behind the resignation of former Defense Secretary James Mattis, and the top U.S. envoy to the global anti-IS coalition Brett McGurk. On Saturday, Navy Rear Admiral Kevin Sweeney stepped down as chief of staff to the Secretary of Defense.

Meanwhile, many military officials, regional analysts and senior U.S. lawmakers insist that IS still remains a capable force, and could regroup if U.S. troops leave. They also warn against abandoning the Kurds, whose forces suffered thousands of casualties fighting alongside the Americans.

Credited as the most effective force in driving IS out of Syria, the Kurdish YPG is seen by Turkey's government as tied to Kurdish insurgents who have carried out acts of terrorism against the Turkish state, and Ankara has repeatedly threatened to attack them in northeastern Syria.

Turkey has already launched previous offensives against the Kurds, taking territory from them in Syria's northwest. Representatives of the Kurdish forces have described the U.S. withdrawal announcement as a shock and a betrayal of trust.

Trump defended his decision on the conviction that other countries should take on the burden of fighting whatever remains of IS, and has made tentative agreements with Turkey's President Recep Erdogan to essentially hand over the job to the Turks. Erdogan has promised that his forces, along with their own allied Syrian fighters, will take up the anti-IS fight — but it's a promise that critics view as a cover for attacking the Kurdish YPG who control territory in Syria's northeast.

Fear of a Turkish assault has prompted the Kurds to increase their engagement with the Assad regime, who they see as potentially providing them protection from the Turks. Security experts also fear that a Turkish offensive would distract the Kurds from their continued battle against ISIS.