[MANCHESTER, New Hampshire] Billionaire businessman Donald Trump won New Hampshire's Republican presidential nominating contest on Tuesday, while US Senator Bernie Sanders of Vermont won the Democratic primary over Hillary Clinton, US television networks said after early results.
Mr Trump's win solidifies his front-runner status in the race to be the party's White House nominee for the Nov 8 election. The reality television star's untraditional campaign has been marked by calls to deport illegal immigrants and temporarily ban Muslims from entering the United States.
Mr Sanders, who describes himself as a democratic socialist, had 56 per cent of the vote in early returns, ahead of former Secretary of State Clinton, the perceived front-runner nationally, who had 42 per cent, according to CNN.
In a statement, Mrs Clinton's campaign acknowledged it had lost in New Hampshire. Campaign manager Robby Mook said in a memo they had "split" the first two nominating contests - Iowa was last week - and said the Democratic nomination would "very likely" be decided in March.
The Clinton campaign said the support of black and Hispanic voters would be key to victory. The next primary races are in Nevada and South Carolina later this month.
"It will be very difficult, if not impossible, for a Democrat to win the nomination without strong levels of support among African-American and Hispanic voters," Mr Mook wrote in a memo titled "March Matters."
"The nomination will very likely be won in March, not February, and we believe that Hillary Clinton is well positioned to build a strong - potentially insurmountable - delegate lead next month," he said.
Some 25 minutes after polls closed at 8pm EST (0100 GMT), Mr Trump was in first place with 34 per cent of the early vote. Ohio Governor John Kasich, who staked the viability of his campaign on the New Hampshire outcome, was in second place with 16 per cent, CNN said.
A logjam of Republican candidates were in a dead heat for third place. Former Florida Governor Jeb Bush, the son and brother of former presidents, had 12 per cent; US Senator Ted Cruz of Texas, who won the Iowa caucus last week, had 11 per cent, and U.S. Senator Marco Rubio of Florida had 10 per cent.