Defense Secretary Ash Carter is endorsing the Arab League's plan to form a joint military force.

Details on how such a force would operate are thin. But the agreement announced Sunday is a telling sign of a new determination among Saudi Arabia, Egypt and their allies to intervene aggressively in regional hotspots.

In remarks Monday during a visit to Fort Drum, New York, Carter called the planned joint force "a good thing."

State Department spokeswoman Marie Harf said the U.S. was waiting to see the exact structure and operational mandate of the joint force.

Arab League officials said a full proposal is to be presented within four months.