After days of conflicting statements about a timeline for President Donald Trump's decision to withdraw American forces from Syria, a US defence official says the process has begun with the removal of some military cargo.
The official says the movement of equipment is part of what the military calls a "deliberate withdrawal" from Syria, where about 2000 troops have been working with a coalition of Syrian Kurdish and Arab fighters to defeat the remnants of the Islamic State group.
The official provided no numbers, but said the equipment withdrawal is under way and that an unspecified number of additional US troops have been brought into Syria to assist with the process, including by providing additional security.
Hours earlier, Colonel Sean Ryan, spokesman for the US-led coalition fighting the Islamic State group, said "the process of our deliberate withdrawal from Syria" has started.
He said the US would not discuss a specific timeline, locations or troop movements out of concern for operational security.
There has been confusion over plans to implement Trump's pullout order and threats from Turkey to attack the Kurdish fighters, who Ankara views as terrorists because of their ties to insurgents within Turkey.
Earlier this week, US National Security Adviser John Bolton said American troops will not leave northeastern Syria until IS is defeated and American-allied Kurdish fighters are protected, signalling a slowdown in Trump's initial order for a rapid withdrawal.
The Britain-based Syrian Observatory for Human Rights, which monitors the conflict in Syria through a network of activists on the ground, said the withdrawal began on Thursday night.
It said a convoy of about 10 armoured vehicles, in addition to some trucks, pulled out from Syria's northeastern town of Rmeilan into Iraq.
A senior Kurdish politician said the Kurds are aware of the US beginning the withdrawal, describing it as "America's decision".
"The Americans have a right to make decisions that are in their country's security and national interests," said Ilham Ahmed, who co-chairs the US-backed Syrian Democratic Council in northeastern Syria.
She added that the peace and stability of areas US forces withdraw from "must be guaranteed", including by putting an end to the Turkish threats and fully eradicating the IS group and its sleeper cells.
Secretary of State Mike Pompeo, who is on a tour of the region, has also sought to reassure the Kurds that they will be safe after US troops withdraw from the country.
"These have been folks that have fought with us and it's important that we do everything we can to ensure that those folks that fought with us are protected," Pompeo said of the Kurds while visiting Irbil, the capital of Iraq's semi-autonomous Kurdish region, after talks in Baghdad.
After initially tweeting about the decision to bring back US troops "now", Trump this week said: "We will be leaving at a proper pace while at the same time continuing to fight ISIS and doing all else that is prudent and necessary!"