Joe Biden meets Chinese president Xi Jinping for the last time as U.S. president on Saturday, but the leaders' goal of lowering tensions before Donald Trump's inauguration is challenged by fresh conflicts over cyber crime,

Scott Bessent, a billionaire hedge fund manager who has become a major fundraiser and economic adviser to Trump, appears to be the leading candidate for the role, two sources familiar with the transition told the BBC's US partner CBS News earlier this week.

President Joe Biden begins his six-day visit to Peru and Brazil on Thursday for the final major international summits of his presidency, while world leaders turn their attention to what Donald Trump 's return to the White House means for their countries.