Democratic presidential candidates Hillary Clinton and Bernie Sanders will face off in four more debates under an agreement reached by the campaigns and the national party on Wednesday.

The additional debates will held in Flint, Michigan on March 6, and two other cities in April and May, with details to be determined later. Clinton has sought a debate in Flint to bring attention to the city's water contamination crisis and Sanders said he wanted it to be scheduled before the Michigan primary on March 8.

Clinton and Sanders are meeting Thursday in a debate at the University of New Hampshire just days before Tuesday's first-in-the-nation primary.

Clinton narrowly defeated Sanders in Monday's Iowa caucuses but Sanders has maintained a solid lead in New Hampshire. It will be the first debate since former Maryland Gov. Martin O'Malley dropped out of the race, leaving just Clinton and Sanders competing for the nomination.

The former secretary of state wanted to debate Sanders in New Hampshire as she tries to close her deficit against the Vermont senator. Sanders, meanwhile, has vowed to take his campaign all the way to the party's summer convention and requested three extra forums to ensure the party will have debates throughout the spring.

Two other Democratic debates are already on the calendar: Feb. 11 in Milwaukee and March 9 in Miami.

In a sign of growing tensions, leaders of the rival campaigns have traded snippy statements over the details of the three debates.

Sanders' campaign wanted one of the debates to be held in California and another in Brooklyn, New York, and questioned why Clinton, a former New York senator, might be reluctant to debate in her adopted home state. Clinton's campaign accused Sanders' team of playing games.

Sanders said Wednesday in an interview with CNN that he got commitments to debate in Michigan and California but could not reach an agreement on holding one in New York City.

"New York City is our largest city. I would have loved to have a debate in that city. But Secretary Clinton has not agreed to do that," Sanders said. "But I believe we are looking at a debate, perhaps, in Pennsylvania or somewhere else."

DNC Chair Debbie Wasserman Schultz, a Florida congresswoman, said the times and locations for the final twodebates will be determined at a later date and the party will work closely with both campaigns as they finalize the remaining details.