US President Donald Trump and Chinese President Xi Jinping have wrapped up a dinner meeting in Argentina lasting about two-and-a-half hours with no immediate comment from representatives for either country.

Trump and Xi sat down with their aides for a working dinner on Saturday night at the end of a two-day gathering of world leaders in Buenos Aires.

Trump said ahead of the dinner he hoped they would achieve "something great" on trade for both countries during a high-stakes summit aimed at defusing a damaging tariffs war between Washington and Beijing.