Barack Obama has won three more states in the battle for the Democratic Party's presidential nomination.

The Illinois senator won by wide margins in the states of Washington, Louisiana and Nebraska.

Mr Obama is neck-and-neck with Hillary Clinton in the nationwide battle to be the party's nominee.

For the Republicans, Mike Huckabee has won the Kansas caucus - although analysts say he still stands no chance of catching front-runner John McCain.

Mr Obama also won caucuses in the US Virgin Islands.

The BBC's James Coomarasamy says the results in the Democratic contests will not be decisive, but they will return the momentum to Mr Obama.

As for the Republicans, our correspondent says that Mr Huckabee's victory in Kansas shows that there is a constituency within the Republican Party that is very suspicious of John McCain, and that Mr McCain has some work to do to unite the party.

Mr Huckabee and third-placed Ron Paul have already been coming under pressure to step aside for the sake of party unity.

For his part, Mr Huckabee said on Saturday that he had no intention of quitting.

"Am I quitting? Let's get that settled right now. No, I'm not," he said.

"I majored in miracles, and I still believe in them."

Going into Saturday's contests, Mr McCain had a wide lead with 719 delegates, to Mr Huckabee's 198 and Mr Paul's 14.

Mr Romney's suspended campaign still has 298 delegates.

On the Democratic side, Mr Obama and Mrs Clinton are facing the prospect of a long drawn-out battle after neither was able to deliver a knock-out blow in Super Tuesday's 22 state contests.

Fight for funds

In advance of the 9 February contests Mrs Clinton had won 1,055 delegates to Mr Obama's 998 of the 2,025 needed to secure victory at the Democratic party convention in August.

Mr Obama's success in Washington, Louisiana and Nebraska will add to his delegate tally and buoy up his supporters.

But Mrs Clinton's campaign says that it expects to take victory at the forthcoming primaries in Maine on 10 February and in Texas and Ohio on 4 March.

As well as fighting for every vote, the candidates are also jostling for funds.

The Obama campaign says it has raised $7m (£3.6m) since Tuesday.

The Clinton camp is now claiming a similar fund raising bump, gaining $6.4m. They earlier admitted that the former first lady had lent her campaign $5m to paper over what aides called a "temporary cash flow problem".

PHOTO CAPTION

U.S. Democratic presidential candidate Senator Barack Obama (D-IL) applauds at the end of his speech at the Virginia Democratic Party Jefferson Jackson dinner in Richmond, Virginia February 9, 2008. (REUTERS)