US election: Mitch McConnell congratulates Biden, White House talks 'ongoing litigation'

Top Republican and Trump ally Mitch McConnell has acknowledged Joe Biden as US president-elect for the first time, congratulating him and vice-president-elect Kamala Harris.

But when speaking to reporters later on, White House press secretary Kayleigh McEnany instead referred to "ongoing litigation" over the election.

The electoral college formally confirmed Joe Biden's victory over Donald Trump on Monday.

Read more: Top Trump ally ends silence to congratulate Biden