SHALIMAR — Gov. Ron DeSantis and U.S. Rep. Matt Gaetz will appear together at the Okaloosa County Administration Building on Friday to sign a bill that effectively bans sanctuary cities in Florida.

The secret surrounding the substance of a widely publicized “major announcement” leaked out about noon Thursday when DeSantis’ spokesperson confirmed the reason for the governor’s visit.

Gaetz, R-Fort Walton Beach, offered no strategic analysis when asked why he thought the governor had chosen ultra-conservative Northwest Florida to sign the controversial bill, which requires “state entities, local governmental entities and law enforcement agencies to use best efforts to support the enforcement of federal immigration law.”

“The governor and I have been wanting to get together again in Okaloosa County for a while now,” he said. “It’s going to be a fun time.”

The bill signing is scheduled for 10 a.m. in the Okaloosa County Commission chambers. Local Republican party officials confirmed a large turnout is expected and elected officials from the county and most of its municipalities will attend.

“We’re excited to have the meeting in Shalimar, and if it is a bill signing, then that’s history we’ll be a part of. All of the town commissioners are coming and we’re proud to have the governor come,” said Mark Franks, the mayor of Shalimar where the Administration Building is located.

Working under the expectation that the Administration Building's parking lot will fill up quickly, the Okaloosa County Sheriff's Office has established overflow parking areas at Miegs Middle School and Shalimar Elementary School. No shuttle service will be provided from either school, according to a news release issued late Thursday afternoon.

Bill sponsor Sen. Joe Gruters, who also is president of the Republican Party of Florida, traveled to Okaloosa County on Thursday afternoon for the event. He called DeSantis' signing of the legislation "a historic day for the people of Florida."

Florida's law will stand as "probably the strongest ban on sanctuary cities in the entire country," Gruters said.

"Our governor and Legislature showed real leadership and a real commitment to the American people," he said. "They've guaranteed that non-citizens won't be treated any better than Americans."

The so-called sanctuary cities bill has been controversial from the outset. Although it passed the state House by a 68-45 margin, it nearly died on its first stop in the state Senate. Sen. Anitere Flores, a Miami Republican, sided with Democrats on the Senate Rules Committee to vote against the measure, and it passed by a skinny 9-8 margin.

The vote to move it off the Senate floor and to the governor was 22-18, also uncharacteristically close.

Conservatives have been trying to get a sanctuary cities bill passed for years, Gaetz said. He credited DeSantis with bringing the necessary “political capital” to the Governor’s Mansion to pull off its passage.

John Whitley, the elected Democratic State Committeeman for Okaloosa County, said he didn’t know if any sanctuary cities even existed in Florida. He accused Gaetz of playing political games.

"This is another dog whistle to Matt's base," Whitley said. "This press conference is a waste of time since there are no sanctuary cities in Florida."

Alachua County is listed on the Center for Immigration Studies website as Florida’s only designated sanctuary city. The county’s sheriff, Sadie Darnell, has declared that her agency will not honor Immigration and Customs Enforcement detainers without being presented a judicial order or criminal warrant, the website said.

Gaetz said several areas in the state act as sanctuary cities even though the bodies that govern them don't publicize their status. The new law defines sanctuary cities by “their conduct and not by their admission,” he said.

Whitley said he was “100 percent” sure protesters would show up to oppose the bill signing. Roxie Tew, another Democratic leader, said Democrats would be on hand and carry signs to protest the legislation.

State Rep. Mel Ponder, R-Destin, said he plans to attend the bill-signing ceremony. He, like Franks, said he supports the sanctuary cities law.

It “puts a line out there statewide” to guide local governments with regard to sanctuary issues, Ponder said.

Pointing to other states where a lack of clear guidance has produced a piecemeal approach to sanctuary city designations, Ponder said that without the new law, “Florida could have been susceptible to that.”

Franks confirmed that Shalimar police were coordinating with the Sheriff’s Office to provide security at the event. Federal and state law enforcement officers will be present to protect Gaetz and DeSantis.

Greg Kisela, Okaloosa's deputy county administrator for operations, said advance teams had come in to prepare the Administration Building for the governor’s visit.

“It hasn’t been a major inconvenience,” Kisela said.

Daily News staff writer Heather Osbourne contributed to this report.