The United States will transfer an observation blimp to the Philippines to help it track maritime activity and guard its borders amid rising tensions in the South China Sea, a U.S. diplomat said on Monday.

Philip Goldberg, U.S. ambassador to the Philippines, said Washington would give Manila, its oldest Asia-Pacific security ally, $42 million worth of sensors, radar and communications equipment.

“We will add to its capability to put sensors on ships and put an aerostat blimp in the air to see into the maritime space,” Goldberg said in an interview with CNN Philippines,

The blimp is a balloon-borne radar to collect information and detect movements in the South China Sea, a Philippine military official said.

China claims almost the entire South China Sea, believed to have huge deposits of oil and gas. Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims to parts of the waters, through which about $5 trillion in trade is shipped every year.

http://www.reuters.com/article/us-southchinasea-china-philippines-usa-idUSKCN0XF1GC