John Kasich drops out of Republican nomination race

Instead, he offered an emotional recount of his exchanges with voters and renewed his call for Americans to spend more time helping one another.

But Mr Kasich acknowledged it was a message that never seemed to resonate.

"The spirit, the essence of America lies in the hearts and souls of us," he said.

"Some missed this message. It wasn't sexy, it wasn't a great soundbite."

Despite his inability to win any contests beyond Ohio, Mr Kasich held on to become the last candidate battling Mr Trump - albeit for only a few hours.

His decision to end his campaign comes a day after his other remaining rival, Texas senator Ted Cruz, announced that he was suspending his campaign.

Mr Kasich was visibly emotional as he thanked his family and staff. "Nobody has ever done more with less in the history of politics," he said.

Earlier, Mr Trump told CNN: "I think John's doing the right thing. I think John will be very helpful with Ohio, even as governor."

Mr Trump stressed that he had a good relationship with the Ohio governor and was willing to consider Mr Kasich as his running mate.

"I would be interested in vetting John," he said.

Touting his two terms as governor and 18 years in Congress, Mr Kasich failed to gain traction with Republican voters in a race dominated by Mr Trump's ability to seize on the electorate's anger and disdain of political insiders.

Although Mr Kasich tried to pitch himself as the best Republican to take on Democrat front-runner Hillary Clinton, the weight of the anti-Trump faction never got behind him.

Viewed widely as a long-shot candidate from the start, Mr Kasich's popularity shot up after his strong second-place finish in New Hampshire's primary in early February.

But from the South to the Midwest, many voters were captivated by his boisterous rivals and his efforts to cast himself as a nicer alternative fell short.

Mr Kasich had pledged to take his campaign all the way to the Republican convention in Cleveland this summer, but his losses in almost all the primaries left him struggling to generate the money and resources needed to sustain a long-term bid.

In an extraordinary effort to send the Republican contest into a contested convention, Mr Kasich and Mr Cruz forged an alliance in late April, going to the states where they were most likely to succeed and deprive Trump the delegates needed to reach the nomination.

As the race grew increasingly nasty on both sides, Mr Kasich largely maintained his vow not to go negative - or, as he told voters, to "take the low road to the highest office in the land".

He did eventually launch a series of blistering criticisms against Mr Trump's candidacy, blasting the businessman for creating a "toxic" environment and preying on people's fears.

Mr Kasich, 63, plans to return to Ohio, where his second term as governor ends in 2018.

"As I suspend my campaign today, I have renewed faith, deeper faith, that the Lord will show me the way forward and fulfil the purpose of my life," he said.