US forces that crossed into Iraq as part of a pull-out from Syria do not have permission to stay and can only be there in transit, the Iraqi military said on Tuesday.

Afghans should not misconstrue America's sudden, contentious and near-total withdrawal from parts of Syria as a precursor to a similar move in Afghanistan, US Defense Secretary Mark Esper said Monday.

United States troops have crossed into Iraq from Syria through the Sahela border crossing in the northern province of Dohuk, Reuters witnesses said on Monday.

US Defense Secretary Mark Esper said on Saturday that all of the nearly 1,000 troops withdrawing from northern Syria are expected to move to western Iraq

Turkey launched a military operation against Kurdish fighters in northeast Syria on Wednesday just days after US troops pulled back from the area

The United States is set to pull troops from five Afghan bases under a proposed deal with the Taliban, the US envoy leading talks with the group said in some of the first confirmed details of a much-anticipated accord.

Iran's supreme leader Ayatollah Ali Khamenei has called on Iraq to demand US troops leave "as soon as possible", warning that Washington is plotting to remove the Iraqi government.

Officials signed a short-term agreement on Sunday to boost South Korea's contribution toward the upkeep of US troops on the peninsula, after a previous deal lapsed amid US President Donald Trump's call for the South to pay more.

Pushing back against Republican opposition, US President Donald Trump reaffirmed his determination to pull US troops out of "endless wars" in Syria and Afghanistan, in an interview that aired yesterday.

A bomb attack claimed by Islamic State killed US troops in northern Syria on Wednesday, weeks after President Donald Trump said the group was defeated there and he would pull out all American forces.

President Donald Trump appeared Monday to water down shock plans for an immediate pullout of US troops from Syria, even as he defiantly claimed his achievements in the conflict should make him a "national hero."

Turkish-backed Syrian forces have reinforced the area around the town of Manbij, a rebel spokesman said on Monday, as they prepare for a withdrawal of US troops following Washington's surprise decision to pull out of Syria.