Sen. Bernie Sanders has agreed to participate in an additional Democratic presidential debate as Hillary Clinton requested, but only if the former secretary of state agrees to attend three additional debates over the next few months.

MSNBC and the New Hampshire Union Leader announced Tuesday that they would host a debate on Feb. 4, but the Democratic National Committee said that it has no plans to sanction the event, meaning that should a candidate attend, they could be excluded by the DNC from future sanctioned debates, reported The Hill.

Up until recently, it appeared as if Clinton wanted to limit the number of debates in order to preserve her lead over Sanders, according to The Daily Caller. However, Sanders has since overtaken Clinton in Iowa, where voters will caucus on Feb. 1, as well as in New Hampshire, where primaries will be held on Feb. 9.

Clinton has now changed her tune and is calling on the DNC to sanction the extra debate. "I'm ready for the debate and I hope Sen. Sanders will change his mind and join us," Clinton told MSNBC's Chris Matthews in a phone interview on Wednesday, according to CNN. "And I think the (Democratic National Committee) and the campaigns should be able to work this out. I've said for, you know, for a long time that I'd be happy to have more debates."

Later on Wednesday, Sanders' campaign criticized Clinton for staying silent when Sanders and former Maryland Gov. Martin O'Malley previously called for more debates, saying that Clinton only cares now because she has fallen in the polls.

"From the beginning of this campaign Sen. Sanders has called for more debates. Secretary Clinton has not. Now she is asking to change the rules to schedule a debate next week that is not sanctioned by the DNC," Sanders' campaign manager Jeff Weaver said in a statement. "Why is that? The answer is obvious. The dynamics of the race have changed and Sen. Sanders has significant momentum. Sen. Sanders is happy to have more debates but we are not going to schedule them on an ad hoc basis at the whim of the Clinton campaign."

The campaign said that for Sanders to participate in the Feb. 4 debate, Clinton must agree to attend three additional debates. One debate must be held in March, April and May, and none should be scheduled for Friday, Saturday or a holiday weekend, far different from the current schedule of debates, which were held mostly on weekends when viewership is low, noted Business Insider. Sanders said that invitations must also be send to both O'Malley and Clinton.

"If the Clinton campaign will commit to this schedule, we would ask the DNC to arrange a debate in New Hampshire on Feb. 4," Weaver said.