The weapons "presented a clear and imminent threat to US and coalition forces," Pentagon spokesman Major General Pat Ryder told journalists, referring to the international coalition against the Islamic State armed group.

"We're still assessing who was operating these weapons, but do know that there are Iranian-backed militia groups in the area that have conducted attacks" in the past, he said.

The US military has around 900 troops in Syria and 2,500 in Iraq as part of the coalition, which was established in 2014 to combat the Islamic State group.

Since war broke out in the Gaza Strip after Hamas attacked Israel on October 7, 2023, Iran-backed groups have repeatedly targeted US forces in Iraq and Syria in response to Washington's support for Israel.

The United States has on multiple occasions responded to such attacks with strikes on those groups.

Syria has seen renewed violence in the last week after four years of relative calm, with Islamist-led rebels seizing towns and swathes of territory from the government across the country's north.

Ryder emphasized that the US military action on Tuesday was "not linked to any broader activities in northwest Syria by other groups."