US President Joe Biden has won North Dakota’s Democratic presidential primary.

The state party announced the results of the mostly mail-in primary on Saturday. The party began circulating ballots in February to voters who asked for them.

Mr Biden’s victory was virtually assured, though seven other candidates were on the primary ballot.

Former president Donald Trump won the North Dakota Republican Party’s March 4 presidential caucuses, taking all 29 delegates.

Mr Biden and Mr Trump have already secured enough delegates for their parties’ nominations, lining up the first presidential rematch election since 1956.

Senator Bernie Sanders won the North Dakota Democratic caucuses in 2016 and 2020.