Updated

Democratic presidential contender Hillary Rodham Clinton has agreed to help one-time candidate Tom Vilsack, who endorsed her on Monday, as he seeks to retire a campaign debt of more than $400,000.

Clinton spokesman Mark Daley said he was uncertain how Clinton would go about raising money for Vilsack, but he conceded that at some point, she would have to contact her supporters. "Someone in her shop is going to have to reach out," Daley said.

Vilsack and his wife, Christie, endorsed Clinton in her bid for the Democratic nomination at an Iowa news conference on Monday. Daley said there was no connection between the fundraising and the endorsement.

"There was no quid pro quo," Daley said. "They have a long history and if she could be helpful she wants to be helpful."

The help for Vilsack comes as one of Clinton's top supporters in New Hampshire disputed reports of another promise in exchange for an endorsement. Bill Shaheen, in an interview with The Associated Press, said suggestions that he withheld his endorsement of Clinton until he was promised an ambassadorship were wrong.

"Did she promise (an ambassadorship)? No," Shaheen said. "That's not how I work. I don't think Senator Clinton is thinking that far down the road and I would be disappointed if she was."

Shaheen joined the Clinton campaign last week as co-chairman of her national and state campaigns. After the endorsement, Shaheen met with bloggers and told them if Clinton wins the White House, he wants to be part of her team negotiating peace in the Middle East.

Last month, a key black Democratic leader in South Carolina negotiated a $10,000 per month consulting contract with Clinton's campaign, a development that came to light when state Sen. Darrell Jackson endorsed the presidential hopeful.

The campaign denied there was any deal made for Jackson's endorsement.

Vilsack announced he would run for president on Nov. 30, about a month before the end of his second term as governor. He ended his campaign Feb. 23, citing an inability to raise enough money.

The Vilsacks became among the most high-profile backers of Clinton's bid. Christie Vilsack said is was a natural decision because her ties to Clinton date to the 1970s. At that time, Christie Vilsack's late brother, Tom, was a lawyer who worked with Clinton during the Watergate-driven impeachment investigation.

In a letter to his backers in Iowa, Vilsack said he will go all out for Clinton.

"Christie and I plan on spending the next 10 months helping Hillary win the Iowa caucuses and the other states necessary to win the Democratic nomination — and after that the White House in 2008," Vilsack said.