Dr. Scott Gottlieb, who advised cruise lines on Covid protocols, told CNBC on Friday that he believed a safe environment could be created on the ships.

Gottlieb’s comments came a day after Florida Republican Governor Ron DeSantis said the state had sued the Centers for Disease Control and Prevention and demanded that the public health agency see cruise ships leave US ports immediately allowed to sail.

Gottlieb, co-chair of an advisory board for Norwegian Cruise Line Holdings and Royal Caribbean, told Squawk Box that companies had sensible guidelines to prepare for when to leave after a Covid hiatus that lasted longer than a while May start operation year.

“They are committed to things like mandatory screening of passengers. Norwegian Cruise Line recently announced that all of their passengers must be vaccinated,” said Gottlieb, who served as the Food and Drug Administration’s appointee from 2017-2019, said the Trump Administration.

Gottlieb also noted that social distancing was possible on the ships, saying “these cruises will not be operated at full capacity.”

“When you start implementing all of these public health recommendations, you start creating an environment that could be pretty safe,” he argued. “I believe you can create a safe bubble around this experience, especially if you compare it to other vacation experiences where you have no control over the surroundings,” he added.

The CDC did not immediately respond to CNBC’s request to comment on Gottlieb’s comments.

Cruise ships were a hotspot for Covid outbreaks in the early days of the global health crisis last year, leading the CDC to issue their no-sail order in mid-March 2020.

While the CDC has issued some guidelines for cruise lines as part of its conditional sail order, the agency has not yet set a date when operators can resume sailing from U.S. ports.

The cruise industry grows impatient after companies borrow billions of dollars in debt and issue new shares to fund operations while sailing revenues dried up. Late last month, a trade group asked the CDC to allow a gradual restart in early July. Operators have stated that they are seeing strong demand for bookings, suggesting that people are starting to feel comfortable returning to cruises.

In a CNBC interview on Wednesday, Carnival CEO Arnold Donald pointed out differences between restrictions in America and other countries around the world where cruises have resumed in some locations.

“A person can fly from the US to another country today. Get on a cruise ship and then return to the US, regardless of whether they have been vaccinated or not,” Donald said at Closing Bell. “But here in the US at the time, even if you were vaccinated, you couldn’t get on a cruise ship.”

Donald commended the Biden government for their work in distributing Covid vaccinations in the US, where approximately 20% of the population is fully vaccinated. He believes the cruise industry and CDC can work together to reach an agreement on sailing.

“The government has made great strides on vaccinations and has taken command of this matter,” said Donald. “We are confident that we can work together and come up with something that would be a workable solution and hope we have some more sailing out of the US this summer.”

– CNBC’s Katie Tsai contributed to this report.

Disclosure: Scott Gottlieb is a CNBC employee and a member of the boards of directors of Pfizer, genetic testing startup Tempus, health technology company Aetion Inc., and biotech company Illumina. He is also co-chair of Norwegian Cruise Line Holdings and Royal Caribbean’s Healthy Sail Panel.