President-elect Donald Trump is not behaving like someone who will soon become "master of the White House", according to China's Global Times newspaper.

"He bears no sense of how to lead a superpower," the opinion piece Monday in the Communist party-controlled tabloid said.

The editorial was reacting to a series of Trump's tweets, posted in light of the news that China had at first seized and then released an underwater U.S. Navy research drone found in international waters within 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 unprecedented act," read Trump's first tweet on Saturday.

"We should tell China that we don't want the drone they stole back. - let them keep it!" he followed up later that day, prompting the newspaper – often regarded as a provocative mouthpiece for China's government – to suggest the president-elect seemed "emotionally upset".