Donald Trump has reached the number of delegates needed to clinch the Republican nomination for president.

His triumph completes an unlikely rise that has upended the political landscape and sets the stage for a bitter fall campaign.

Mr Trump was put over the top in the delegate count by a small number of the party's unbound delegates who told the AP on Thursday they will support him at the convention.

It takes 1,237 delegates to win the Republican nomination for president - Mr Trump has reached 1,238.

With 303 delegates at stake on June 7, Mr Trump will easily pad his total, avoiding a contested convention this summer.