US Secretary of Defence Lloyd Austin has not ruled out the option of additional strikes on Iran-linked groups unless attacks on American forces in Iraq and Syria cease, Al Jazeera reports.

“These attacks must stop, and if they don’t stop, then we won’t hesitate to do what’s necessary, again, to protect the troops,” Austin told reporters at a news conference in Seoul.

Austin’s comment comes hours after the secretary of defence said it conducted overnight air attacks in eastern Syria.