WASHINGTON, D.C.— -- The Pentagon says China has agreed to return a U.S. Navy underwater drone that had been seized in international waters in the South China Sea. The incident had sparked a diplomatic protest from the United States demanding the return of the drone, which is used for oceanographic research.
"We have registered our objection to China's unlawful seizure of a U.S. unmanned underwater vehicle operating in international waters in the South China Sea," said Peter Cook, the Pentagon press secretary, in a statement released Saturday. "Through direct engagement with Chinese authorities, we have secured an understanding that the Chinese will return the UUV to the United States."
No details were provided on how the drone would be returned to U.S. control.
Earlier Saturday, China's Foreign Ministry had said the U.S. and China were using military channels to appropriately handle the seizure of the drone.
The drone was seized Thursday 50 nautical miles northwest of Subic Bay in the Philippines by the crew of a Chinese naval vessel that had been shadowing the USNS Bowditch, a U.S Navy oceanographic vessel. The crew had been conducting research in the area.
The American ship was in the process of recovering one of two unmanned underwater vehicles (UUV) known as an "Ocean Glider." The UUV was "gathering military oceanographic data such as salinity, water temperature and sound speed ... in accordance with international law," Cook said Friday.
A small boat launched from the Chinese Navy warship and retrieved the other drone from the water and brought it to the Chinese vessel.
The American crew contacted the Chinese vessel by radio multiple times, demanding the return of the drone. The demands were ignored, the Pentagon said.
The only response the Chinese vessel gave was "we are returning to normal operations" as it pulled away from the Bowditch, according to the Pentagon.
"The UUV is a sovereign immune vessel of the United States," Cook said Friday. "We call upon China to return our UUV immediately, and to comply with all of its obligations under international law."
A U.S. defense official said there was no indication as to why the Chinese would want to pick up an unclassified drone used for ocean research.
The South China Sea has become an international focal point for China, the United States and other countries in the region.
China has claimed seven reefs in the Spratly Island chain as its own, essentially dredging them into islands. There are also territorial claims over the Paracel Islands located east of Vietnam and the Scarborough Shoal, 200 miles west of the Philippines.
New satellite imagery released publicly by a Washington think-tank this week seems to indicate that China has begun placing "significant" military defenses on the artificial islands it has built up in the Spratly Islands.