The U.S. says it will be keeping nearly 300 troops, including Air Force commandos armed with combat aircraft and helicopters, in the Philippines through the end of the month. It's part of a military build-up sure to inflame tensions with China in the South China Sea.

The Pentagon says the U.S. will also begin sending forces on increased rotations into the Philippines to beef up training and to support increased military operations in the region. And for the first time the U.S. revealed that American ships have started conducting joint patrols in the South China Sea with the Philippines, a somewhat rare move not done with many other partners in the region.

Defense Secretary Ash Carter announced the plans during a news conference Thursday with Philippine Defense Secretary Voltaire Gazmi.