The US government made it tougher on Wednesday for Americans to book trips and do business with Cuba, making good on a pledge by President Donald Trump to roll back his Democratic predecessor’s move toward warmer ties with Havana,  Associated Press reported.

The restrictions, which take effect on Thursday, are aimed at preventing the military, intelligence and security arms of Cuba’s Communist government from benefiting from American tourists and trade, the White House said. 

Now off-limits to U.S. citizens are dozens of Cuban hotels, shops, tour companies and other businesses included on a lengthy American blacklist of entities that have links to Cuba’s military, intelligence or security services. And most Americans will once again be required to travel as part of heavily regulated, organized tour groups run by U.S. companies, rather than voyaging to Cuba on their own.

The stricter rules mark a return to the tougher U.S. stance toward Cuba that existed before former President Barack Obama and Cuban President Raul Castro restored diplomatic relations in 2015. They come as President Donald Trump tries to show he’s taking action to prevent U.S. dollars from helping prop up the Cuban government.