POWERFUL AIR FORCES

On Monday, Kerry met Saudi Foreign Minister Saud al-Faisal and British Foreign Secretary Philip Hammond, and participated in a meeting of more than a dozen countries, including Arab Gulf States, on the conflict in Libya.

A senior administration official said US plans "to expand our efforts to defeat (Islamic State) were discussed without specifics" during meetings but declined to elaborate.

Several Arab states have powerful air forces, including Saudi Arabia and the United Arab Emirates. Saudi Arabia has also already agreed to host US training of Syrian opposition fighters.

But many Gulf Arab states have been reluctant to be seen aggressively joining the US campaign, fearing in some cases reprisals by extremists or forces loyal to the Syrian government.

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

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.

US expands campaign against IS	First US airstrikes in expanded Iraq fight