US President Joe Biden named his former top Covid-19 aide Jeff Zients as new White House chief of staff. He replaced Ron Klain as chief of staff, one of the most crucial positions in an administration gearing up for a possible re-election campaign.

Biden praised Klain for his tireless work, and said he is "confident that Jeff will continue Ron's example of smart, steady leadership, as we continue to work hard every day for the people we were sent here to serve," in a statement.