Ted Cruz has waved his white flag in the race for the Republican US presidential nomination after Donald Trump clinched a resounding victory in Indiana.
Billionaire businessman Trump still needs about 200 delegates to formally secure the nomination, but Cruz's decision to end his campaign removed his last major obstacle.
"Ted Cruz - I don't know if he likes me or he doesn't like me - but he is one hell of a competitor," Trump said of his last fierce competitor whom he had dubbed "lyin' Ted" during the campaign.
Trump, in a victory speech that was much lower key than usual, promised victory in November's general election, vowing anew to put "America first".
Indiana was viewed as the last gasp for fiery Texas senator Cruz. The conservative campaigned aggressively in the state, securing the support of Indiana's governor and announcing businesswoman Carly Fiorina as his running mate, but he lost momentum in the closing days.
He had clung to the hope that he could keep Trump from reaching the 1,237 delegates needed for the nomination and push the race to a rare contested convention.
"I've said I would continue on as long as there was a viable path to victory; tonight I'm sorry to say it appears that path has been foreclosed," Cruz told sombre supporters in Indianapolis.
Ohio governor John Kasich is now the only other Republican left in the race, but he has won just one primary - his home state - and trails Trump by nearly 900 delegates.
Kasich pledged to stay in the race, with his campaign manager saying he would continue to "offer the voters a clear choice for our country".
Only about half of Indiana's Republican primary voters said they were excited or optimistic about any of their remaining candidates becoming president, according to exit polls. However, most said they probably would support whoever won for the party.
Meanwhile, Vermont senator Bernie Sanders scored a victory over Hillary Clinton in Indiana, but the outcome is not likely to slow the former US secretary of state's march to the Democratic nomination.
Heading into Tuesday's voting, Clinton had 92% of the delegates she needed.
Sanders said he had won a "great upset victory" in Indiana and expected "more victories in the weeks to come".
"The Clinton campaign thinks this campaign is over. They're wrong," he said.
Sanders said he had an "uphill climb" to the nomination but was "in this campaign to win and we are going to fight until the last vote is cast".