Nikki Haley says making Trump the Republican candidate is a 'Biden win'

Nikki Haley sought to warn Republican voters away from rival Donald Trump after he defeated her in Tuesday's New Hampshire primary, saying nominating the controversial US ex-president would spell victory for Joe Biden in November.

"The worst kept secret in politics is how badly the Democrats want to run against Donald Trump," she told a watch party in New Hampshire after US networks projected she would lose the primary. "A Trump nomination is a Biden win," she said.