MANILA, April 14 (UPI) -- The United States and the Philippines are conducting joint patrols of the South China Sea in response to Beijing's island-building activities in the maritime region.
"With a presence here, it will deter uncalled for actions by the Chinese," said Philippine Defense Secretary Voltair Gazmin, Voice of America reported.
U.S. troops are also expanding their presence in the Philippines with rotational forces and equipment, U.S. Defense Secretary Ashton Carter said Thursday in Manila.
The first joint patrol took place in March, making the Philippines the second country to conduct joint maritime patrols with the United States after Japan, according to a defense official.
Air operations are also part of an agreement that was signed in January. The operations involve aircraft and pilots are engaging in joint exercises across the Philippines, The New York Times reported.
The U.S. plan is to place 200 pilots and crewmembers, six aircraft and three helicopters at the location once known as Clark Air Base, north of Manila.
The base is now called Philippine Air Force Facility.
"Our planners are examining ways on how to make such patrols part of our regular activities," Gazmin told reporters.
Manila is a claimant to the coral reefs where China has built 1,200 hectares of artificial land. Satellite imagery showed Beijing has built runways and military facilities in an area where the country has also claimed the waterway.
Carter said the purpose of the joint patrol is not to increase tensions. Hundreds of U.S. troops and 10 aircraft will remain after the joint exercises end Friday.
In January, the Philippine Supreme Court approved a 10-year military cooperation agreement with the United States that allows the U.S. military to build facilities and deploy troops.