Calling the Obama administration’s Cuba policies “terrible and misguided,” President Donald Trump on Friday announced the overturning of the previous White House’s liberalization of travel and business practices to the island nation in front of a friendly crowd in South Florida.

“We now hold the cards. The previous administration eases of restrictions on travel and trade … only enrich the Cuban regime,” he said in Miami, announcing alterations to the Obama-era policies.

Signing a directive with a flourish amid officials like Sen. Marco Rubio, R-Fla., Rep. Mario Diaz-Balart, R-Fla., and Republican Gov. Rick Scott, Trump said his changes are “effective immediately,” but a senior White House official on Thursday said the existing Obama policies will remain in place until new rules and regulation are written by several federal departments.

Trump administration officials say the changes are aimed at preventing U.S. dollars from flowing into the coffers of what the administration views as, in the words of a senior official, “repressive members of the Cuban military government.” The new rules will place restrictions on Americans’ ability to travel to Cuba, and slap restrictions — though with exceptions for airlines and cruise lines — on American firms’ ability to do transact with Cuban businesses that are owned by its military and intelligence services.

Trump declared that, under his watch, the United States will not lift a single sanction on Cuba “until all political prisoners are free.”

The president vowed to very strictly enforce all U.S. laws when it comes to Cuba.

Trump declared that his policy changes, once implemented, will “very strongly restrict American dollars” flowing into the coffers of the military and intelligence services that he called the “core of the Castro regime.”

He vowed to “enforce the ban on tourism” to Cuba and to “enforce the embargo.”

And he challenged the Cuban government to enter into talks with U.S. officials toward a new agreement that would be in the “best interests” of Americans, Cubans and Cuban-Americans.

Trump faces skepticism from a both sides of the aisle in turning back the clock on Cuba policy, but as long as the statutory embargo on the island nation remains on the books, such critics are limited in what they can do to affect policy.