Democratic candidates Hillary Clinton (left) and Bernie Sanders during the NBC/YouTube presidential debate in Charleston, S.C., on Sunday, Jan. 17, 2016. (AP Photo/Mic Smith)

MASON CITY, Iowa -- Presidential hopeful Bernie Sanders on Wednesday proposed holding an additional three Democratic debates, as the jockeying among the party’s candidates continued over how often they should face off in the weeks ahead.

Under rules put forth by the Democratic National Committee, the party’s presidential debates are limited to six this cycle, four of which have already taken place.

In a television interview Wednesday, former secretary of state Hillary Clinton called on Sanders to agree to participate in a debate next week in New Hampshire that hasn’t been sanctioned by the DNC and said she hoped the DNC would agree to sponsor it.

[Hillary Clinton says she wants to debate]

Sanders initially balked at the idea after news surfaced that the Feb. 4 debate was being planned by the New Hampshire Union Leader and MSNBC, saying he did not want to take part in an event not blessed by the DNC.

In a statement issued Wednesday night, Jeff Weaver, Sanders’s campaign manager said that Sanders has long been interested in more debates.

“Secretary Clinton has not,” Weaver said. “Now she is asking to change the rules and ask for a debate next week that is not sanctioned by the DNC. Why is that? The answer is obvious. The dynamics of the race have changed and Senator Sanders has significant momentum.”

Weaver said Sanders would be “happy to have more debates” but added: “We are not going to schedule them at whim of the Clinton campaign.”

He said Sanders would like to see additional debates in March, April and May -- and none of them on Fridays or Saturdays or holiday weekends, as has previously been the case.

[Why Bernie Sanders doesn't participate in organized religion]

If the Clinton campaign would commit to that schedule, Weaver said, Sanders would join Clinton in asking for the DNC to arrange a debate in New Hampshire next week.

The latest skirmishing over the debate schedule comes just five days before the Iowa caucuses. Clinton’s once-formidable lead in the polls has evaporated in recent weeks, and Clinton and Sanders are now locked in a tight race.

A third Democratic candidate, former Maryland governor Martin O’Malley, who is running a distant third, has made clear that he is eager to debate more often, including on Feb. 4.

Sanders was campaigning here in Mason City as his campaign manager’s statement was released. Officials at the venue estimated the crowd size at 1,100.

During his remarks Wednesday night, Sanders chided Clinton for leaving the nation’s first caucus state to hold a fundraiser in Philadelphia sponsored by leading executives of a large investment firm.

Sanders, who has sought to make an issue of Clinton’s ties to the financial sector, told the crowd that “my opponent is not in Iowa tonight.”

“She is raising money from a Philadelphia investment firm,” Sanders said. “Frankly I would rather be here with you.”

On Wednesday, Clinton was set to attend a fundraiser held by a group that includes the chairman and chief executive officer and other executives at Franklin Square Capital Partners. According to the Philadelphia Inquirer, the firm “employs Ivy League-educated money managers and salespeople with experience at big Wall Street firms.”

Rocker Bon Jovi was scheduled to play at the event.

In recent weeks, Sanders has been critical of a series of paid speeches that Clinton gave to corporate and financial interests, suggesting that it undercuts her ability to push for needed Wall Street reforms.

Clinton has argued that new regulations she has proposed are tougher than reforms Sanders are pushing, which center on breaking up large banks.

[Sanders steps off the campaign trail for a ‘constructive’ 45-minute meeting with Obama]

Sanders was also absent from Iowa recently. On Tuesday, he held a pair of rallies in Minnesota, which holds its caucuses on March 1. On Wednesday morning, he met with President Obama in Washington.

On Wednesday night, Sanders was introduced here by actress and political activist Susan Sarandon, who called Sanders “a candidate who has the courage to stand and do the right thing when it’s not popular.”

“For me, gender is not what’s important,” Sarandon said in an obvious reference to Clinton. “Issues are what’s important.”