MIAMI – Faced with protests, political pressure and a lawsuit, Carnival Corp. announced Monday it will allow Cuban-born passengers to book cruises to the island but will delay the trips if Cuba does not change its policy barring nationals from returning by sea.

Carnival CEO Arnold Donald said in a written statement that the cruise line is continuing negotiations with Cuba aimed at resolving the issue prior to a scheduled May 1 cruise by its Fathom brand from Miami to Cuba – the first such sail in more than 50 years that is part of the ongoing thaw in U.S.-Cuba relations.

The 704-passenger Adonia plans to sail every other week to three Cuban ports: Havana, Cienfuegos and Santiago de Cuba. “We want everyone to be able to go to Cuba with us,” Donald said. “We remain excited about this historic opportunity to give our guests an extraordinary vacation experience in Cuba.”

The decision follows protests last week by Cuban-Americans outside Carnival’s headquarters in the suburb of Doral. Miami-Dade County Mayor Carlos Gimenez – who was born in Cuba – also suggested in a letter that Carnival might be violating the county’s human rights ordinance by discriminating against a specific class of people.

In addition, two Cuban-Americans who were prevented from buying tickets on the May 1 cruise because they were born in Cuba filed a potential class action civil rights lawsuit in Miami federal court last week. And Secretary of State John Kerry said during a visit to Miami on Friday that Cuba should change its policy and that Carnival nevertheless should allow anyone to travel on its ships.

Cuba does permit Cuban-born people to arrive by air to the island. Donald said Carnival was continuing discussions so that travel on its ships would “be on a level playing field” with airlines and air charters.

“Again, we remain confident that we will reach a positive outcome and we continue to work full speed ahead in preparing for our every-other-week sailings from Port Miami to Cuba,” he said.

Carnival, the world’s largest cruise line, operates 10 cruise brands around the world with 100 ships that visit some 700 ports, according to the company statement.