07:06Newsday25/11/2020 07:06 GMT: Biden says White House co-operation 'sincere'BBC World Service Duration: 53 minutes Wed 25th Nov 2020, 07:06 on BBC World ServiceAvailable for over a yearListen nowUS President-elect Joe Biden has unveiled officials for six important posts. Show more GenresNewsFormatsMagazines & ReviewsBrandNewsday Source: BBC Online