The US military said on Tuesday its partners in air strikes against Islamic State militants in Syria included Jordan, Bahrain, Saudi Arabia, Qatar and the UAE.

In a statement, it added the US military had taken action to disrupt "imminent attack" against the US and Western interests by "seasoned Al Qaeda veterans" who had established a safe haven in Syria. "These strikes were undertaken only by US assets," it said.

The statement said the US had launched strikes from warships in international waters in the Red Sea and the North Arabian Gulf.

It said Bahrain, Jordan, Qatar, Saudi and the UAE had "also participated in or supported the air strikes against (Islamic State) targets. All aircraft safely exited the strike areas," it said.

"I can confirm that US military and partner nation forces are undertaking military action against (Islamic State) terrorists in Syria using a mix of fighter, bomber and Tomahawk Land Attack Missiles," Rear Admiral John Kirby, Pentagon press secretary, said in an earlier statement.

"Given that these operations are ongoing, we are not in a position to provide additional details at this time."

The strikes took place hours before Obama goes to New York for the UN General Assembly where he will try to rally more nations behind his drive to aggressively take on Islamic State.

"We will provide Obama had shied away from getting involved in Syria's civil war a year ago, seeing no positive outcome for the United States, but the rise of Islamic State and the beheading of two American captives forced him to change course.

General Lloyd Austin, commander of the US military's Central Command, made the decision to conduct the strikes under authorization granted to him by Obama, Kirby said.

"We will provide more details later as operationally appropriate," Kirby said.

Ongoing strikes by the US and partner nations in Syria could include around 20 targets, a US official said on Monday, speaking on condition of anonymity.

The official said some of the strikes employed Tomahawk missiles launched from at least one US ship at sea. - Reuters