The seizing of an unmanned US Navy drone by the Chinese is an “unpresidented [sic] act,” President-elect Donald Trump tweeted early Saturday.

The USNS Bowditch, which has a civilian crew, was about to retrieve the underwater device Thursday when it was snapped up by a Chinese warship in the South China Sea.

“China steals United States Navy research drone in international waters – rips it out of water and takes it to China in unpresidented [sic] act,” Trump wrote on Twitter. He’s since deleted the misspelled tweet.

The $150,000, 10-foot drone was part of a scientific mission collecting oceanographic data. It’s the first time in recent history China has taken a US naval vessel, a Navy spokesman said.

Bonnie Glaser, senior adviser for Asia at the Center for Strategic and International Studies, said the seizure of the drone occurred inside the exclusive economic zone of the Philippines and appeared to be a violation of international law.

The United States issued a formal diplomatic complaint over the incident which comes amid increasing tensions with the Chinese as Beijing continues a military buildup in the area where the drone was taken.

Trump added to the rancor with a Dec. 2 telephone conversation with Taiwanese President Tsai Ing-wen and his comments that he did not feel “bound by a one-China policy.”

Chinese officials said Saturday they’re working with their American counterparts “on appropriately handling this matter through channels between the two militaries.”

With Post Wire Services