Washington: Republican White House hopeful Ted Cruz easily defeated frontrunner Donald Trump in the race to be the party nominee for the 2016 presidential election in the Saturday caucus in Wyoming.

With all votes counted, Texas Senator Cruz won 66.3 percent of the ballots in the western state, far ahead of his nearest rival, Florida Senator Marco Rubio, who earned 19.5 per cent of the vote, US media reported.

Trump, the bombastic real estate magnate leading in polls and in delegates to the Republican national convention, came in third with a measly 7.2 per cent of the vote.

With these results, Cruz wins nine delegates, while Rubio and Trump scored one delegate, with another delegate uncommitted.

A Republican primary was also held in the US capital Washington, but results were not expected until later. Nineteen delegates are at stake.

The biggest prizes will be on Tuesday, when primaries are held in five delegate-rich states — Florida, Illinois, Missouri, North Carolina and Ohio.