The United States will withdraw 1,000 troops from northern Syria while Turkey's military operation there continues.

The US "is preparing to evacuate" about 1,000 troops from northern Syria "as quickly and safely as possible," Defense Secretary Mark Esper said on October 13 in an interview with CBS.

The move comes a week after President Donald Trump announced the re-mobilization of dozens of U.S. troops joining the Kurdish militia in northern Syria, giving the green light a Turkish military operation. The launch was aimed at the Syrian Democratic Forces (SDF), Washington's main ally in the fight against the Islamic State (IS).

"In the past 24 hours, we know the Turks are likely to expand their offensive campaign more south than originally planned and also to the west," Esper said. "We also know that the SDF is seeking agreement with Syria and Russia to fight Turkey in the north."

According to Esper, the remaining US troops in Syria are trapped in a conflict between SDF and Turkey. "I spoke to the President last night, after discussing other things with the national security team, and the President issued an order that we will start withdrawing troops from northern Syria." for more info.

When asked if the US has the right to respond with firepower, Esper said US troops "have the right to self-defense and will act in case of necessity".

Turkey launched a military operation in northeastern Syria on 9 October to target the SDF's location, with the core of the Kurdish People's Protection Units (YPG), which it considers terrorist.

Turkey's campaign raises fears that ISIS forces could take advantage of the chaos to rise after the failure earlier this year. More than 130,000 people had to leave their homes due to the intense fighting. The Turkish military announced it had captured the important town of Ras al-Ayn near the border on October 12, while also controlling many villages in northern Syria.

Many countries oppose Turkey to launch a military operation in Syria, but Turkish President Recep Tayyip Erdogan has said he will not stop the campaign unless he has repelled the Kurds as planned.