The Trump administration announced tight new restrictions Wednesday on American travel and trade with Cuba, implementing policy changes President Trump announced five months ago to reverse Obama administration normalization with the communist-ruled island.

Under the new rules, most individual visits to Cuba will no longer be allowed, and U.S. citizens will again have to travel as part of groups licensed by the Treasury Department for specific purposes, accompanied by a group representative. Americans also will be barred from staying at a long list of hotels and from patronizing restaurants, stores and other enterprises that the State Department has determined are owned by or benefit members of the Cuban government, specifically its security services.

The new rules “are intended to steer economic activities away from the Cuban military, intelligence and security services . . . and encourage the government to move toward greater economic freedom” for the Cuban people, said a senior administration official, one of several authorized by the White House to brief reporters on the changes on the condition of anonymity.

Commercial relations with Cuba are to be similarly restricted to prevent any exchanges with the 180 entities on the State Department’s list.

TIMELINE: Trump’s Cuba policy

Administration officials said the new regulations, which will take effect Thursday, would not affect certain existing transactions. For visitors, that means anyone who has “completed at least one travel-related transaction (such as purchasing a flight or reserving accommodations) prior to” publication of the new regulations in the Federal Register on Thursday.

For businesses, all those who have signed contracts before publication may proceed with them, officials said. That presumably would include both John Deere and Caterpillar, both of which reportedly signed recent distribution contacts with Cuba.

President Barack Obama restored diplomatic ties with Havana in 2015 and issued regulatory changes that allowed increased commercial relations and expanded travel to Cuba.

Trump said during his campaign that he would “terminate” the Obama normalization if Cuba would not cut a “better deal” with the United States. In a policy speech in June in Miami’s Little Havana neighborhood, he said that “our policy will seek a much better deal for the Cuban people and for the United States of America. We do not want U.S. dollars to prop up a military monopoly that exploits and abuses the citizens of Cuba.” He ordered the Treasury, Commerce and State departments to begin writing the new rules that have now been announced.

Much as Obama used his regulatory authority to loosen restrictions within an ongoing U.S. economic embargo on Cuba, Trump has now changed those regulations to re-tighten them.

Sen. Robert Menendez (D-N.J.), one of several Cuban American lawmakers who opposed the Obama opening, called the new regulations “a step in the right direction” but said their effectiveness was diminished by allowing existing transactions to be grandfathered in.

The Obama changes were widely supported by U.S. businesses. Engage Cuba, a national business coalition that supports lifting the embargo and expanding trade and travel, called the new regulations a “more convoluted, confusing and counterproductive approach to Cuba policy” that will hurt the Cuban private entrepreneurs it claims to be helping, and abandon U.S. leadership to Russian efforts to regain influence in the hemisphere.

Under new Trump administration rules, most individual visits to Cuba will no longer be allowed. (Adalberto Roque/AFP/Getty Images)

"The great irony of releasing these regulations while President Trump stands in Communist China is dumbfounding, but not surprising," Engage Cuba President James Williams said in a statement.

U.S. airlines and cruise ships will continue to operate in Cuba under the new regulations.

Although the amount of trade under the Obama changes has not expanded as much as anticipated, a number of U.S. business and agricultural entities have continued to seek contracts in Cuba.

While “tourism” to Cuba has remained prohibited under the embargo, American travel to the island under specified categories has nearly tripled, to almost 300,000 last year.

The most significant change under the new regulations is the elimination of the individual “people-to-people” category of educational travel. As before the Obama opening, most visitors to Cuba will again have to travel in licensed groups. One remaining exception appears to be the “support for the Cuban people” category, which requires travelers to “engage in a full-time schedule” of unspecified “meaningful interaction with individuals in Cuba” and activities that support civil society.

All travelers are prohibited from staying at many hotels throughout the country that the State Department has said are connected to various holding companies said to be all or partly owned by the security services.

Instead, the new regulations encourage Americans to stay in rooms rented by private citizens and to eat in private restaurants that have been allowed for a number of years as part of a growing Cuban private sector.

The prohibited list also includes a number of Cuban ports, and the massive Mariel economic zone, shopping centers and individual stores such as Trasval, Cuba's equivalent of Home Depot in Havana. Transactions with companies producing Cuba's most popular soft drinks, such as Tropicola, also are prohibited.

Administration officials said that all travelers returning to U.S. ports and airports from Cuba would have to maintain proof of their activities in Cuba.

Separately, the administration in recent months has significantly reduced the size of the U.S. Embassy in Havana, suspended issuance of U.S. visas to Cubans there, advised Americans not to travel to the island and expelled 15 Cuban diplomats from Havana’s embassy in Washington.

The State Department has said those actions were in response unspecified “attacks” that have caused health problems affecting two dozen American diplomats in Cuba. Administration officials said Wednesday that those actions were unrelated to the new regulations.