Democratic presidential candidates Hillary Clinton and Bernie Sanders speak during a break at the Jan. 17 Democratic presidential debate n Charleston, S.C. (Mic Smith/AP)

AMES, Iowa -- Hillary Clinton and Democratic rival Sen. Bernie Sanders have agreed to additional debates during the Democratic primary, but are still squabbling over dates and locations. The arrangement also still needs the approval of the Democratic National Committee.

Both campaigns said Saturday they would welcome a debate next week in New Hampshire. Each attached caveats, however, and proposed different terms for adding three additional debates to the previously sanctioned DNC schedule.

The third Democrat in the race, former Maryland governor Martin O'Malley, has said he would debate anywhere, anytime, and O'Malley campaign spokeswoman Lis Smith said that he has agreed to the additional four debates.

Clinton is ahead nationally but roughly tied with Sanders in Iowa, where the first presidential selection contest will be held  Monday. Both candidates were campaigning in the state Saturday. Sanders, an independent senator from Vermont, leads the former secretary of state in New Hampshire, where primary voting takes place Feb. 9.

The two campaigns issued dueling statements Saturday. Clinton campaign chairman John Podesta noted that Clinton had already agreed to add a debate on Thursday in New Hampshire, and called for an additional debate to take place in Flint, Mich., where a cost-saving decision led to serious lead contamination in the city's water. He did not specify when that Michigan debate should take place.

"We should use the spotlight of the presidential campaign to keep the focus on Flint, and to lift up the historic underlying issues that Flint and too many other predominantly low-income communities of color across America are struggling with every day," Podesta said.

The Flint water crisis has become a focus of liberal outrage, and Clinton highlighted the issue during the last Democratic debate in South Carolina.

Sanders campaign manager Jeff Weaver issued a statement later Saturday needling the Clinton camp.

"After refusing for months to participate in more debates, Secretary Clinton requested that the Democratic National Committee rules be changed and that a new debate take place in New Hampshire next week. We agreed pending an agreement on three future debates in March, April and May," Weaver said.

The Clinton campaign has not agreed to debates Sanders proposed on March 3 in Michigan and April 14 in New York, Weaver said, but has "apparently agreed to May 24 in California."

"The Clinton campaign, after not accepting Michigan, now says they want it. We are pleased to do it on March 3 before the Michigan primary provided the Clinton campaign will agree to Brooklyn, New York, on April 14," Weaver continued. "Why won't they debate in Brooklyn? What's the matter with Brooklyn?"

Clinton's campaign is headquartered in Brooklyn, and Sanders was born and raised in the New York borough, and retains a strong Brooklyn accent despite decades as a Vermonter.

Last week, MSNBC and the New Hampshire Union Leader announced that they planned to hold a debate not sanctioned by the DNC on Thursday, five days before the New Hampshire primaries. And while O'Malley and Clinton readily agreed, Sanders's campaign had previously said it would only agree to the debate if it was sanctioned by the DNC and followed by three more such events.

The Sanders campaign also insisted that the debates not be held on Fridays, weekends or holiday weekends.

Even the limited areas of agreement between Clinton and Sanders - the Thursday debate and three more with times and locations not yet determined - adds to the pressure for the DNC to expand its previously approved schedule.

"We are in communication with both campaigns to reach consensus, but nothing's been nailed down," a DNC spokesman said Saturday.

Anne Gearan contributed from Des Moines.