Former US President Donald Trump won the Republican primary in the state of North Dakota, according to Sky News.

This comes ahead of a series of contests known as "Super Tuesday," which is expected to strengthen his lead in the race to secure the party's nomination for the presidential election.

Trump achieved a comfortable victory in North Dakota over Nikki Haley, his last remaining competitor for the Republican Party's nomination for the presidential election.

Trump is expected to dominate the contests on Tuesday, when Republicans cast their votes in 15 states and one US territory on the biggest day of the primaries.

Haley, the former US ambassador to the United Nations, secured her first victory in the primaries on Sunday, in Washington, D.C., but she does not seem to have a chance to secure the nomination after Trump's wins in the first eight contests, and he is expected to continue his victories in virtually all remaining contests.

Trump is focusing on the potential electoral competition with the current Democratic President Joe Biden next November.