Before the ships docked, company officials had said that dozens of people had recovered, but 45 people were not well enough to travel and would remain on board.

The Coast Guard issued a notice this week that all foreign-flagged cruise ships carrying more than 50 people must be prepared to care for any sick passengers and crew members at sea for an “indefinite period of time” or to seek medical assistance from other countries during the coronavirus pandemic.

In a statement Thursday, Mr. Udine, the county commissioner, said he tried but failed to have the passengers quarantined on a Navy base or one of the company’s private islands, or at a port outside Florida’s coronavirus “hot zone.”

“The cruise company wanted to just drop people off and let them fly home,” he said.

Senator Rick Scott of Florida also said that all the passengers should be held in quarantine and tested. But federal health officials stressed that they would no longer be holding cruise ship passengers in quarantine.

“That was earlier in the pandemic,” Dr. Cindy Friedman, a member of the Centers for Disease Control and Prevention’s cruise ship task force, told Broward County commissioners earlier this week. What asymptomatic passengers need, she said, is a mask and to go straight home.