Without mentioning President-elect Donald Trump's name, Chinese President Xi Jinping appeared to signal his concern that Trump's protectionist rhetoric on the campaign trail could send the U.S.-China relationship into another valley.

Joe Biden met Chinese counterpart Xi Jinping for the final time as president Saturday in Peru as the specter of Donald Trump's return to the White House took center stage at the Asia-Pacific economic summit.

Donald Trump has made a tougher stance toward China central to his pitch on foreign policy, even as Joe Biden and Xi Jinping sought to lower tensions before the next president takes office.