President-elect Donald Trump tweeted Saturday evening that China should be told to “keep” the US Navy underwater drone it recently seized from South China Sea waters and agreed to return.

“We should tell China that we don’t want the drone they stole back.- let them keep it!” he tweeted.

Earlier on Saturday, Trump had called the capture — an incident that added to existing tensions between the US and China — an “unprecedented” act.

“China steals United States Navy research drone in international waters — rips it out of the water and takes it to China in an unprecedented act,” he tweeted, after deleting a widely mocked version of the tweet that used the misspelling “unpresidented.”