Beijing rejected on Monday US president-elect Donald Trump's claim that it had stolen a US unmanned underwater vehicle, saying that was "totally inaccurate".

Foreign Ministry spokeswomen Hua Chunying said, "We don't like the word 'steal,'" in response to Trump's pair of tweets over the weekend, accusing Beijing of "stealing" the equipment in an "unprecedented act".

On Sunday, after Beijing and Washington announced the drone would be returned, Trump tweeted: "We should tell China that we don't want the drone they stole back. - let them keep it!"

The Chinese lifeboat that retrieved the 3-meter-long drone adopted a "responsible and professional" attitude in investigating and verifying the device, she added.

"The reason is simple and straightforward," Hua said. "Imagine you found something on the street, you at least have to examine the item first and check the claimant before returning it."

When asked about whether China would change its restraint toward Trump's tweets after he becomes US president on Jan 20, Hua replied: "We pay attention to the government's action."

The drone was discovered and retrieved by the Chinese Navy to "prevent danger to the safe navigation of passing ships and personnel", Hua said. It was operating about 93 kilometers northwest of Subic Bay off the Philippines.

Hua said that China has always opposed the United States conducting reconnaissance and military surveys within Chinese waters. "It has threatened China's security and sovereignty. China will maintain vigilance against the relevant US activities and take necessary measures in response," she said.

He Weibao, a researcher of US foreign affairs at the Chinese Academy of Social Sciences, said the Chinese Navy has the right to retrieve unidentified objects that could potentially threaten safe navigation, even in international waters.

"It would be irresponsible for China not to have picked up the device," said He. "The anxiety displayed in the US over the drone episode could raise suspicion of espionage, given how the US has increased reconnaissance efforts in the region."

zhangzhihao@chinadaily.com.cn