FARGO, N.D. — Minnesota Gov. Mark Dayton is warning federal officials not to presume his state will approve a permit for a Red River flood diversion around the cities of Fargo and Moorhead, Minnesota.

In a recent letter to the director of the Office of Management and Budget and an assistant Army secretary, Dayton said he’s “deeply disappointed” that the Army Corps of Engineers seems to be disregarding concerns Minnesota has raised about the project. He said it’s essential that the Corps respect Minnesota’s permit process and not prematurely begin construction.

“You should understand that a favorable permit decision by Minnesota is by no means guaranteed, and I take exception to actions by the U.S. Army Corps of Engineers and its non-federal sponsors to suggest otherwise or attempt to advance construction in the absence of the required Minnesota permits,” Dayton said.

Terry Williams, project manager for the corps, declined to comment specifically on Dayton’s complaints or the tone of his letter.

“We have been working with the Minnesota DNR since 2008 on this project and we will continue to work with them through the permitting process and address the concerns that they have identified,” Williams said. “We’re confident we can work through issues.”

Fargo Mayor Tim Mahoney, who is slated to take over next year as board chairman of the Fargo-Moorhead Diversion Authority, issued a statement Tuesday saying his city is working with the Minnesota Department of Natural Resources to address its questions and respect Dayton’s timeline.

“I truly believe in direct and honest communication; let’s have a constructive dialogue instead of communicating through third parties or separately exchanging talking points in the media,” Mahoney said. “It is time to put the hard feelings behind us and return to the collaboration that makes the Red River Valley the best place in the world to live.”

The $2.1 billion diversion channel is designed to move water around the flood-prone Fargo metropolitan area, but would need a staging area south of the cities to store water in times of serious flooding. A group representing about 20 cities and townships in North Dakota and Minnesota upstream of the north-flowing river filed a lawsuit in August 2013 asking for a cheaper project that doesn’t flood farmland.

The Minnesota DNR has signed off on an environmental review of the project, but says it is still investigating whether the project is compatible with land use and water management plans in the area and whether it does enough to help people whose land would be intentionally flooded.

Fargo residents will vote in November on whether to extend a sales tax to help pay for flood control.