Carnival Cruise Line, along with other major carriers, are canceling trips to Cuba and offering on-board credits or refunds in the wake of new Trump administration restrictions on traveling to the island nation.

On June 4, the Treasury Department announced it was ending Obama-era policy of allowing “group people-to-people educational travel” to Cuba. An announcement from the Commerce Department specifically banned cruise ship travel to Cuba, effective June 5.

“Cuba continues to play a destabilizing role in the Western Hemisphere, providing a communist foothold in the region and propping up U.S. adversaries in places like Venezuela and Nicaragua by fomenting instability, undermining the rule of law, and suppressing democratic processes,” Treasury Secretary Steven Mnuchin said. “This administration has made a strategic decision to reverse the loosening of sanctions and other restrictions on the Cuban regime. These actions will help to keep U.S. dollars out of the hands of Cuban military, intelligence, and security services.”

The abrupt change has left cruise lines and passengers – some of whom book months or even a year ahead – scrambling.

According to Cruise Critic, passengers on board the June 3 sailing of the Carnival Sensation were diverted to Cozumel instead of Cuba and given a $100 on-board credit. Guest who were planning to travel to Cuba through the end of July 2019 are being given the option of keeping their reservations and receiving a $100 on-board credit; changing itineraries and receiving a $50 credit; or canceling and receive a full refund.

The cruise line said it is working to secure alternative itineraries for the future and will be notifying customers in the coming days.

Royal Caribbean is also modifying its scheduled Cuba cruises, according to Cruise Critic.

All 2019 sailing planned for Cuba will have alternative ports in the Caribbean. Guests have the option of canceling and receiving a full refund or keeping their sailing date with the new itinerary and receiving a 50 percent refund.

Norwegian Cruise Line, Viking, MSC and other cruise lines have announced similar changes.