Ohio Governor John Kasich has dropped out of the presidential race after struggling to gain traction against Republican front-runner Donald Trump, US media report.
Mr Kasich did not have a path to secure the nomination outright, but pledged to lobby for his candidacy during the Republican convention in July.
Mr Trump holds a commanding lead and is closing in on the nomination.
Despite being a popular governor, Kasich only won his home state.
Texas Senator Ted Cruz dropped out of the race on Tuesday after losing to Mr Trump in the Indiana primary.
Mr Kasich cancelled events in Washington and announced an evening event in his home state on Wednesday.
Earlier on Wednesday, he released a Star-Wars themed advert describing himself as the “only hope” against Donald Trump.