Secretary of Defense Lloyd Austin says the move was in response to continued attacks on US forces in Syria and Iraq.

In a statement on Wednesday, US Defense Secretary Lloyd Austin said the “self-defence strike” was carried out by two of the air force’s F-15 fighters in response to recent attacks on US forces.

“The president has no higher priority than the safety of US personnel, and he directed today’s action to make clear that the United States will defend itself, its personnel and its interests,” the statement said.

Amid rising tensions since the Israel-Hamas war erupted on October 7, Washington has said its troops and their allies have been attacked at least 40 times in Iraq and Syria by Iran-backed forces, with 45 servicemen suffering traumatic brain injuries or minor wounds.

Late last month, the Pentagon said the US struck two IRGC and Iran-linked facilities in Syria following attacks on US personnel.

In Wednesday’s statement, Austin urged an end to the attacks.

“The United States is fully prepared to take further necessary measures to protect our people and our facilities. We urge against any escalation,” he said.

The United States has 900 troops in Syria and 2,500 more in Iraq, on a mission to advise and assist local forces trying to prevent a resurgence of ISIL (ISIS), which in 2014 seized control of large swathes of both countries before it was eventually defeated.

The US has said its strikes are not connected with the Israel-Hamas war, amid concerns about a regional escalation of the crisis.

Iran backs both Hamas, which has governed Gaza since 2006, and the Lebanese armed group Hezbollah, which has been engaged in skirmishes with Israel along the Israel-Lebanon border.