Ted Cruz has announced he is ending his campaign for the US Republican presidential nomination, after losing heavily to Donald Trump in the Indiana primary.

Trump, a New York businessman who is unpopular with many in his own party, is almost certain to be the nominee.

Earlier, Cruz called Trump a "liar" who was unfit to be president.

In the Democratic battle, Bernie Sanders is projected to beat Hillary Clinton in Indiana.

He trails Mrs Clinton in the all-important delegate count but after this victory he told Associated Press news agency: "Clinton campaign thinks this campaign is over. They're wrong."

Cruz's advisers had targeted Indiana as the senator's best hope of halting Trump's march to the nomination.

"We gave it everything we've got, but the voters chose another path," he told supporters in Indiana.

The verbal attacks between him and Trump had reached a new intensity on Tuesday.

Cruz attacked the billionaire businessman as "totally amoral", "a pathological liar" and "a serial philanderer".

Trump responded by calling Ted Cruz is a "desperate candidate trying to save his failing campaign".

But hours later, after Cruz announced he was quitting the race, Trump praised him as a "tough, smart competitor".