— Gov. Roy Cooper on Monday promised legal action if North Carolina is not exempted from the Trump Administration's offshore drilling plans.

Florida won an exemption shortly after the administration announced plans to explore new drilling operations up and down the Atlantic Coast. The decision drew speculation that Florida was treated differently because it has a Republican governor or because President Donald Trump owns coastal property there.

But Cooper said he'll stick with what Interior Secretary Ryan Zinke said publicly at the time: That Florida's heavy reliance on tourism and consideration of the "local and state voice" led to his decision to remove Florida from the plan.

"If that's the reason to exempt Florida then it's the reason to exempt North Carolina," said Cooper, who was backed during a news conference Monday at Wrightsville Beach by locals opposed to offshore drilling.

This rationale has been repeated up and down the Atlantic Coast and in Pacific states that would also see their coasts open to offshore drilling, should the Trump Administration's plan continue to advance on its current trajectory. Cooper joined governors from six other Atlantic states last week on a letter asking Zinke to reconsider the drilling plan. The governor also spoke to Zinke on the phone, he said, and the secretary agreed to visit North Carolina at some point.

If diplomacy doesn't bring results, Cooper said North Carolina will turn to the courthouse.

"If North Carolina is not exempt from offshore drilling, we will sue the federal government," he said.

Others have suggested that leaving Florida out of the plan opens a legal foothold for such a suit. Sierra Club Executive Director Michael Brune told The Washington Post this month that federal agency actions, by law, can't be "arbitrary and capricious" and that Florida's exemption "seems to be the definition of arbitrary and capricious."

Cooper said Monday that, in exempting Florida, the federal government has admitted drilling represents a threat to coastal tourism. He also pointed to the state's fishing industry. A spill isn't the only concern for fishermen. The seismic explorations used to find drilling spots could harm marine life and drive schools away. The Cooper administration recently asked several companies that do this work to submit more information to the state on this potential effect.

In announcing Florida's exemption, Zinke called the state "unique" and said its coasts are "heavily reliant on tourism as an economic driver." The head of the Bureau of Ocean Energy Management has since told Congress that Zinke's announcement doesn't mean drilling off Florida's coast is definitely off the table, saying instead that it will be considered as formal decisions are made.