China will return a US Navy drone seized in the South China Sea "in an appropriate manner," state media reports, while US president-elect Donald Trump suggests Beijing should "keep it".
"In order to prevent the device from causing harm to the safety of navigation and personnel of passing vessels, the Chinese naval lifeboat verified and examined the device in a professional and responsible manner," the Xinhua news agency reported on Sunday, citing China's Defence Ministry.
"The Chinese side has decided to hand over it to the US in an appropriate manner," ministry spokesman Yang Yujun said in a statement late on Saturday, Xinhua said.
It was not clear what that entailed.
Yang also said Beijing "resolutely opposes" what it said was the frequent dispatch of US military vessels and aircraft to carry out reconnaissance work within Chinese waters.
"China will continue to be vigilant against the relevant activities on the US side, and will take necessary measures in response," he said.
A US Defence Department had earlier said an agreement had been reached with China on Saturday on the return of the drone.
"Through direct engagement with Chinese authorities, we have secured an understanding that the Chinese will return the (vehicle) to the United States," spokesman Peter Cook said in a statement.
The unmanned drone known as an ocean glider was being used to collect military oceanographic data as part of routine operations near the Philippines when a Chinese Navy PRC DALANG III-Class ship intercepted it.
Meanwhile, Trump blasted China for what he called an "unprecedented act."
"China steals United States Navy research drone in international waters - rips it out of water and takes it to China in unprecedented act," Trump said on Twitter, correcting an earlier tweet for which he was ridiculed for calling the act "unpresidented".
In an additional tweet, Trump later added: "We should tell China that we don't want the drone they stole back.- (sic) let them keep it!"
He had already prompted a formal complaint from Beijing when he accepted a phone call from Taiwan's President Tsai Ing-wen, breaking the US' decades-old policy of avoiding formal ties with the island, which China regards as a renegade province.
Territorial disputes and navigation issues in the South China Sea have caused tensions between China, its neighbours and the United States.
New satellite images this week showed China has significantly strengthened its military capabilities on contested islands in the South China Sea.
