(CNN) FBI officials are set to meet with Florida Gov. Ron DeSantis and US Sen. Rick Scott about concerns that Russians hacked at least one Florida county ahead of the 2016 election.

The recent Mueller report contained the first-ever public US government claim that hackers successfully compromised a county's network in the lead-up to that year's election. The report states "the FBI believes that this operation enabled the GRU to gain access to the network of at least one Florida county government."

That county has never been identified.

Chris Hartline, a spokesman for Scott, told CNN that the FBI reached out to schedule an appointment "in the next week or so."

Scott, in a letter to FBI Director Christopher Wray, wrote "I am requesting that the FBI provide any evidence to corroborate those claims to Congress and the Florida Department of State within seven days. Specifically, I would like to know which Florida county was compromised."

A spokesperson for DeSantis told CNN that a meeting with the FBI will also be held with his office within the next few weeks.

"They won't tell us which county it was. Are you kidding me? Why would you not say something immediately?" DeSantis said Thursday at an event in Miami, according to the Tampa Bay Times. "We're looking for answers."

Florida officials, who have long maintained that Russian efforts had not been successful there, tell CNN that they were shocked by the claim.

"The Florida Department of State has no knowledge or evidence of any successful hacking attempt at the county level during the 2016 elections," said Sarah Revell, a spokesperson for the Florida Department of State. "Upon learning of the new information released in the Mueller report, the Department immediately reached out to the FBI to inquire which county may have been accessed, and they declined to share this information with us. The Department maintains that the 2016 elections in Florida were not hacked. The Florida Voter Registration System was and remains secure, and official results or vote tallies were not changed."

The FBI declined to comment for this story.

In an interview with The New York Times on Friday, Florida Republican Sen. Marco Rubio said there was an intrusion and that hackers were "in a position" to change voter roll data but said that it does not appear they did.

Rubio, a member of the Senate Intelligence Committee, told the Times, "My biggest concern is that on Election Day you go vote and have mass confusion because voter registration information has been deleted from the systems."

"I don't believe the specific victims of the intrusion have been notified," Rubio said. "The concern was that in a number of counties across the country, there are a couple of people with the attitude of: 'We've got this; we don't need your help. We don't think we need to do what you are telling us we need to do.' "

CNN has reached out to counties around Florida. Miami-Dade officials do not believe their system was the one compromised.

"Miami-Dade County has no indications of possible or actual elections systems compromise from internal monitoring or external parties," said Miami-Dade County Supervisor of Elections Christina White.

Deputy Supervisor Robert Rodriguez told CNN that it was alerted by its election software company to a potential phishing campaign, but confirmed with its own technical staff that no emails had been received by that county.