WASHINGTON, May 3 (Xinhua) -- U.S. Republican presidential candidate Ted Cruz on Tuesday bowed out of the race after his defeat in the GOP's Indiana primary, delivering a heavy blow to Republicans currently eyeing a contested convention this summer to snatch the party's nomination from Donald Trump.

"From the beginning, I've said that I would continue on as long as there was a viable path to victory," Cruz told his supporters at a rally in Indianapolis, Indiana. "Tonight, I'm sorry to say it appears that the path has been foreclosed."

Though he had already been mathematically eliminated from reaching the 1,237 delegates required to win the nomination on the first ballot at July's GOP convention before Tuesday's Indiana primary, Cruz and the anti-Trump movement within the party had for long hoped to prevent Trump from getting the 1,237 delegates before the convention in July and create a contested convention where other candidates might get nominated after the first round of voting.

However, after the suspension of Cruz's candidacy, there left no doubt that Trump, the New York billionaire developer famous for his blunt and occasionally incendiary remarks, would be the GOP's presumptive presidential nominee.

The once crowded Republican field has dwindled. Despite his flagging campaign and winning only one contest, Ohio Governor John Kasich made it clear on Tuesday evening that he would stay in the race.

However, the Kasich campaign's hope to force Trump into a contested convention in July became dimmer after Trump's sweeping victory Tuesday night.

With his big win in Indiana, Trump is guaranteed at least 30 of the state's 57 delegates up for grabs, pushing his delegate count over the 1,000 threshold.

However, Trump is unlikely to formally clinch the nomination until June 7, when California and five other states vote and a total of 303 delegate will be up for grabs.

In order to win the GOP nomination, a candidate must win 1,237 delegates. Trump entered the contest on Tuesday with 956 pledged delegates and another 41 unpledged ones, while Kasich, his only rival now, had only 153.