The tribe’s battle to secure federal recognition for its land has hinged on the legal interpretation of the Indian Reorganization Act, a landmark 1934 law sometimes known as the “Indian New Deal.” Steven Senne/Associated Press

The Mashpee Wampanoag Tribe will lose its reservation status by order of the US Secretary of the Interior, the tribe’s leader said Saturday.

Tribe Chairman Cedric Cromwell said he had learned of the plans Friday afternoon in a phone conversation with officials from the Bureau of Indian Affairs that included agency director Darryl LaCounte.

“It’s painful, but I’m not surprised," Cromwell said in an interview.

In a statement posted on the tribe’s website, Cromwell said the Mashpee would continue to fight for sovereignty over its ancestral lands.

“We will not rest until we are treated equally with other federally recognized tribes and the status of our reservation is confirmed,” he wrote.

“Today’s action was cruel and it was unnecessary. The Secretary is under no court order to take our land out of trust,” he added. “He is fully aware that litigation to uphold our status as a tribe eligible for the benefits of the Indian Reorganization Act is ongoing.”

The tribe’s battle to secure federal recognition for its land has hinged on the legal interpretation of the Indian Reorganization Act, a landmark 1934 law sometimes known as the “Indian New Deal.”

Conner Swanson, a spokesman for the Department of the Interior, confirmed the plans on Saturday. Representative Bill Keating, a longtime ally of the tribe, denounced the move as “cruel and nonsensical."

“In a time of national health and economic emergency, the Secretary of the Interior should be reaching out to help all Native American tribes," Keating said in a statement.

The tribe has waged a protracted legal battle to build a $1 billion casino on reservation land in Taunton. Last month, the tribe was dealt a major setback when the US Court of Appeals for the First Circuit ruled in favor of a group of nearby residents who oppose the casino, holding that the Bureau of Indian Affairs did not have the authority to designate land to the tribe in 2015.