USNS bowditch
The oceanographic survey ship USNS Bowditch, shown here on September 20, 2002, which deployed an underwater drone seized by a Chinese Navy warship in international waters in the South China Sea on December 15, 2016. U.S. Navy/Handout/File photo via Reuters

China returned an underwater drone to US on Tuesday after it was seized by the Chinese naval vessel on Dec. 15. The exchange happened some 92km northwest of Subic Bay in the Philippines.

Pentagon spokesman Peter Cook confirmed on Monday that both countries were working out the logistical details of the drone's return. China's Foreign Ministry also said that they were having unimpeded talks about it.

Navy Capt. Jeff Davis said that the drone was collecting unclassified scientific data within the exclusive economic zone of the Philippines, particularly, in Subic Bay in South China Sea. The area has been disputed as a sovereign territory by China and the Philippines.

However, instead of claiming a sovereignty freedom, the US insisted on freedom of navigation including the right to conduct training and other operations in the sea using its naval vessels.

Davis said that the drone was clearly marked that it was a US property and it cost about $150,000 (AU$206,700). The drone has an off-the-shelf technology.

Some observers considered the incident as the most significant dispute between a Chinese fighter jet and a US Navy surveillance leading to the death of a Chinese pilot.

President-elect Donald Trump commented on the actions of China saying that the country did not need the drone they stole back. He also said to let China keep it.

Foreign Ministry spokeswoman Hua Chunying said that the Chinese Navy possessed a professional attitude and responsibility when it found an unnamed object. She explained that it was part of the Navy's responsibility to identify the object before it would be returned to the owner. She also said that the drone was not stolen from the US.