WASHINGTON — The Trump administration scuttled a landmark deal enabling Cuban baseball players to play on Major League Baseball teams and declared it illegal, the latest move to roll back the warming of relations between the United States and Cuba that began in the Obama administration.

Senior Trump administration officials said they were rescinding an Obama-era decision that deemed Cuba’s baseball league to be separate from the Cuban government. The U.S. economic embargo on Cuba prohibits Americans from doing business with Cuba’s government, so the Obama administration’s ruling had cleared the way for an agreement between MLB and the Cuban Baseball Federation reached late last year.

That deal was designed to allow Cuban baseball players joining U.S. teams without having to defect, as had been the case in years past. Now that the ruling that underpinned the deal is being voided, “that agreement will not be able to proceed in its current form,” one official said.

“Major League Baseball has been informed of the dangers of dealing with Cuba,” a second senior official said.

Hard-line critics of the Cuban government, such as Sen. Marco Rubio, R-Fla., have been ramping up pressure over the issue since Cuba earlier this month released the list of the first group of players who are eligible to sign direct contracts with MLB teams. There were 34 players on that list, with some expected to be able to sign with U.S. teams and start playing as early as this year.

The Cuban Embassy in Washington and MLB did not immediately respond to requests for comment Monday.

Under the U.S. economic embargo on Cuba passed by Congress decades ago, the administration has discretion to decide whether an entity like the Cuban Baseball Federation is too closely aligned with the government — in this case Cuba’s sports ministry — to be considered independent. Senior Trump administration officials said they couldn’t understand why the Obama administration had deemed the federation to be independent, calling it “an entity of the Cuban government.”

But former Obama administration officials said the goal of the policy had been to enable Cuban players to join U.S. teams without having to defect to the United States, which often involved dangerous journeys at the hands of human smugglers. Players would often pay to be smuggled into a third-party country from which they could join MLB.

Ben Rhodes, a former National Security Council official who led the Obama administration’s effort to restore U.S. relations with Cuba, said the Trump administration’s new approach is “cruel and serves no purpose.”

“It’s an humanitarian issue for these Cuban players and their families,” Rhodes said.

Still, a senior Trump administration official said the Obama administration’s policy effectively institutionalized the individual trafficking of Cuban players, arguing that under the MLB deal, the players were still being trafficked, just by the Cuban government instead of smugglers. Under the MLB deal, U.S. teams signing Cuban players were to pay a fee for each player to the Cuban Baseball Federation.

“One way or another, it’s human trafficking,” the official said.

The Trump administration has sought to deny the communist-run island revenues that help sustain the government there, which national security adviser John Bolton has deemed part of a “troika of tyranny” along with Venezuela and Nicaragua. Rubio said Monday on Twitter that the deal reached last year amounted to the “legalized trafficking of persons” in which Cuba only lets its baseball players leave “if MLB pays them a ransom.”

“The agreement with #MLB seeks to stop the trafficking of human beings, encourage cooperation and raise the level of baseball. Any contrary idea is false news,” the Cuban Baseball Federation said Monday on Twitter. “Attacks with political motivation against the agreement achieved harm the athletes, their families and the fans.”

Major League Baseball released a statement Monday afternoon saying, "We stand by the goal of the agreement, which is to end the human trafficking of baseball players from Cuba."

With the deal scuttled for now, any agreements for Cubans to play on U.S. teams would require specific licenses from the Treasury Department exempting them from the prohibition. It’s unlikely the Trump administration would move quickly to grant those licenses.

“The MLB deal with Cuba solved a horrible human trafficking problem,” said James Williams, who runs the group Engage Cuba that promotes closer ties between the U.S. and the island. “By breaking that deal, the White House now owns this and exposes Cuban players to human rights abuses.”