It's all over for Hillary, but will Obama ask her to be his No.2 in fight for White House?

Rather than concede the loss to Mr Obama, the New York senator told a cheering crowd she would consult supporters and party leaders to decide the future of her campaign.

Mrs Clinton praised her opponent and vowed to help unite the party to defeat Republican John McCain, 71, in November's election.

But she added defiantly: 'This is a long campaign and I will be making no decisions tonight.'

It's not over: Hillary Clinton addresses supporters last night. She refused to conceded defeat to Hillary

Wiinner: Barack Obama claims victory in the race to be Democratic candidate for the White House

Mrs Clinton urged supporters to contact her campaign's Web site, saying: 'I want to hear from you ... Share your thoughts with me.'

Some supporters speculated Mrs Clinton was jockeying for the job of vice president on Mr Obama's ticket.

The New York senator earlier said she was open to the idea, and the Obama campaign said it was keeping its options open.

Many of her top supporters spoke openly of her potential vice presidential prospects.

Lanny Davis, a former White House special counsel under President Bill Clinton, said  he was initiating a petition to press Mr Obama to select her for the second spot on the ticket. He said Clinton did not encourage or discourage the step.

'If he doesn't have her, I think he can still win. With her on the ticket, he can't be beat,' Davis added.

Mrs Clinton's national finance chairman, Hassan Nemazee, said he was also pushing an Obama-Clinton ticket, claiming that together they would be able to raise $200 million to $250 million for the general election.

Clinton, 60, hailed Obama, 46, and his supporters 'for all they accomplished', saying they had run an extraordinary race for the Democratic presidential nomination. The party delegates will meet at a Denver convention in August.

'Senator Obama has inspired so many Americans to care about politics and empowered so many more to get involved,' she told supporters. 'And our party and our democracy is stronger and more vibrant as a result.'

Despite Obama's victory, Mrs Clinton planned to concentrate on winning uncommitted delegates to her side, her campaign said.

Over and out: A grim looking Bill Clinton watches his wife last night

Still hopeful: A supporter of Hillary Rodham Clinton holds up her hands with the message "We Love HRC" written on them

'She is still a candidate for president and is still making her case as to why she should be the nominee for president,' spokesman Mo Elleithee said.

She's going to be taking the next couple of days to make her case to delegates, to unpledged delegates and superdelegates and take stock after that.

'Now that the voting's over, she has the ability to go to these remaining delegates and say look at where we stand. Look at who closed stronger.'

Clinton supporters last night chanted 'Yes, she can' and 'Yes, she will'.

Patricia Williams, 45, a stay-at-home mother from the Bronx area of New York City, was visibly upset by Clinton's apparent defeat.

'I've been crying all day. You see my eyes?' she said. 'Whatever she does I will support her, but I wish she would take it to the convention.'

Former New York Congresswoman Elizabeth Holtzman, who was in the crowd, said she was reminded of her own feelings after losing a close race for New York's U.S. Senate seat in 1980.

Ms Holtzman said when she lost, her campaign tried to keep going for a couple days, waiting for the counting of absentee and military ballots before conceding defeat.

'Rather than coming to grips with reality, we kept it going and it was a mistake,' she said.

'It would have been better to have acknowledged it.'