The U.S. government made it tougher on Wednesday for Americans to book trips to 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.

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.

They fill in the regulatory detail on a Trump policy speech in June, in which the Republican president called for a tightening of restrictions. Trump said then that the Cuban government continued to oppress its people and former President Barack Obama had gone too far in a 2014 diplomatic breakthrough with Washington's former Cold War foe.