Almost 800,000 passenger bookings around the world have been affected by sudden new US rules banning cruise lines from Cuba.

Cruise trade body Clia said in a statement that the US government has “announced the immediate implementation of new regulations that prohibit previously approved cruise line travel to Cuba from the US”.

Clia added: “Without warning, Clia cruise line members are forced to eliminate all Cuba destinations from all itineraries effective immediately.

“This affects nearly 800,000 passenger bookings that are scheduled or already under way.

“All these bookings had been made under a general licence previously issued by the US government that authorised ‘people to people’ travel to Cuba.

“The new rules effectively make it illegal to cruise to Cuba from the US.

“While this situation is completely beyond our control, we are genuinely sorry for all cruise line guests who were looking forward to their previously booked itineraries to Cuba.”

The move, announced by Trump administration officials, aims to roll back a US-Cuba thaw that began under former president Barack Obama.

Virgin Voyages will ditch Cuba from its itineraries and has told agents it would have a new port-of-call to replace Havana next week.

Its inaugural programme in 2020 had included four and five-night Havana After Dark itineraries which included a visit to Unesco World Heritage site, Old Havana.

Norwegian Cruise Line said it is closely monitoring the situation and will contact guests and travel partners with information when details are available.

Royal Caribbean is changing itineraries for June 5 and six sailings that were due to visit Cuba.

“All 2019 sailings on the Majesty of the Seas and Empress of the Seas will have alternative ports in the Caribbean,” the company said.

“Guests will have the option to cancel their current booking for a full refund, or to keep their sailing date with a new itinerary and receive a 50% refund.

“We are working on alternate itineraries for 2020 sailings and will share those details with guests and travel partners as they become available.

“We appreciate our guests’ patience and flexibility as we adjust to accommodate the new regulation.”

Carnival Corporation said its brands would no longer be permitted to sail to Cuba “effective immediately”.

The company said: “Carnival Corporation confirmed that due to changes in US policy, the company will no longer be permitted to sail to Cuba effective immediately.

“Currently, Carnival Corporation is sailing to Cuba on Carnival Cruise Line and Holland America Line, and Seabourn has been scheduled to begin sailing in November to Cuba. Additional details will be provided for currently booked cruises by the cruise lines.”

MSC Cruises said it will modify all its cruise itineraries previously scheduled to call in Cuba.

MSC Armonia and will instead call at either Key West, Florida; Costa Maya, Mexico; George Town, Cayman Islands; or Cozumel, Mexico instead of Havana.

Guests currently on board MSC Armonia and their travel agents have been offered the various options, including onboard credit and the possibility to change ship and itinerary. Cancellation fees will be waived.

More: US cruise lines face Cuba ban