Updated

Thousands of U.S. and Philippine troops, along with Australian special forces, have begun annual military drills to be able to rapidly respond to a range of potential crises, including in the disputed South China Sea.

U.S. Marine Lt. Gen. John Toolan said Monday that Defense Secretary Ash Carter will fly to the Philippines to witness some of the 11-day Balikatan exercises. The drills will see the deployment for the first time of a highly mobile rocket system that has been used in war zones including Afghanistan.

Philippine military officials say a key exercise will involve U.S., Australian and Philippine forces retaking an oil rig seized by hostile units.

The U.S. and the Philippines say the exercises are not directed against China, which has opposed the drills.