Former Massachusetts governor Mitt Romney has won Nevada's Republican presidential caucuses, further cementing his run for the White House.

Newt Gingrich and Ron Paul were in a tight race for second, with former Pennsylvania senator Rick Santorum finishing last.

With votes from 71% of the precinct caucuses in Nevada counted, Mr Romney had 48%, Mr Gingrich 23%, Mr Paul 19% and Mr Santorum 11%.

A total of 28 Republican National Convention delegates were at stake in caucuses held across the state.

Mr Romney won at least 10, Mr Gingrich at least four, Mr Paul at least three and Mr Santorum at least two. Eight were still to be determined.

That gives Mr Romney a total of 97 delegates , including endorsements from Republican National Committee members who will automatically attend the convention and can support any candidate they choose. 

Mr Gingrich has 30, Mr Santorum 16 and Mr Paul seven. It will take 1,144 delegates to win the Republican nomination.

Sky News' US Political Analyst Jon-Christopher Bua said: "In this first Western state contest Mitt Romney came through with the expected 'blowout'. Here his Mormon faith was an asset.

"However, this continued bitter battle for the for the hearts and minds of the conservative base among Romney and his GOP rivals, especially Newt Gingrich, is pushing him further and further to the right.

"If Romney becomes the nominee the positions he has taken to win this prize will make it even more difficult for him to move back to the centre to and capture the independents - the 'deciders' - in the general election."

Speaking to supporters after the main count, Mr Romney thanked Nevada voters for their confidence in him and vowed to take it all the way to the White House.

Mr Romney's decisive win comes four days after he cruised to a double-digit victory in Florida's primary, cementing his status as front-runner and leaving his rivals struggling to keep pace.

Nevada was the West's first nominating contest.

The state has struggled with a high percentage of people defaulting on mortgages and the nation's highest unemployment rate, at 12.6%.

Mr Romney unleashed a sharp attack on the US president, whose economic policies he said have "made these tough times last longer".

"President Obama seems to believe America's role as leader in the world is a thing of the past.

"I believe the 21st century will be and must be an American century," he said to cheers from his backers.

Mr Romney had an advantage of cash and a strong political organisation as the contest heads to states that appear friendly, including Colorado and Minnesota.

Mr Gingrich promised his supporters that he too would continue to pursue the Republican nomination, scotching rumours that he was planning to drop out of the race.