Washington - US President Donald Trump has vowed to revisit all of his predecessor's diplomatic successes and failures, but is he ready to slam the door on Cuba?On Friday, he is expected to unveil a new policy on relations with Cuba after Barack Obama painstakingly restored ties with the communist-run island.Although many Americans support the decision and the US business community has welcomed moves to reopen trade, Trump's hardline campaign rhetoric won him support among influential Cuban exiles in Florida.The White House has not let much slip, but a radical turnaround such as a renewed break in diplomatic relations does not yet appear to be on the cards.Instead, Trump may announce a return to restrictions on US tourists heading to Cuba and businesses signing partnerships with Cuban firms.That would be meant to press Raul Castro's government toward democratic reform and appease Cuban-American voters, many of whom fled communist rule.US Secretary of State Rex Tillerson on Tuesday acknowledged that increased co-operation helps both countries and provides opportunities for downtrodden Cubans.But he also cited the "dark side" of Cuba's regime, saying Trump's review had concluded that some renewed business relations help fund the regime."Cuba has failed to improve its own human rights record. Political opponents continue to be imprisoned. Dissidents continue to be jailed," he told senators.Financial support"And as we're enjoying the benefits on the economic and development side, are we inadvertently or directly providing financial support to the regime?""Our view is: 'we are'," he added, answering his own question.That view resonates with Cuban-Americans such as Senator Marco Rubio, the son of anti-Castro immigrants, who has long warned that détente is moving too fast."I am confident the president will keep his commitment on Cuba policy by making changes that are targeted and strategic and which advance the Cuban people's aspirations for economic and political liberty," he said.Trump accused Cuba of "cruel despotism" in May, vowing to support its people's hopes for democracy, which raised ironic cheers from rights supporters more used to his cosying up to Saudi Arabia, Turkey and other autocratic states.But watchdog groups such as Human Rights Watch are sceptical of a return to the terms of the half-century Cold War stand-off, with its total trade embargo and no diplomatic ties."The previous administration was right to reject a policy that hurt ordinary Cubans and did nothing to advance human rights," said Daniel Wilkinson, the group's managing director for the Americas."The fact that Obama's approach hasn't led to political reform in Cuba after just a few years isn't reason to return to a policy that proved a costly failure over many decades."Tourism boomOn the economic front, business interests on both sides of the Florida Straits are wary of a return to a rigorous enforcement of the still-active US sanctions legislation.About 50 female Cuban entrepreneurs who have benefited from the island's limited free-market opening have even written to Trump's daughter and adviser Ivanka.Inviting her to the island to see for herself, the women insist that "millions of Cubans" now benefit from increased tourism and trade."A setback in the relationship would bring with it the fall of many of our businesses and with this, the suffering of all those families that depend on them," they wrote.The previous US administration softened many of the restrictions lifting American travel to Cuba, triggering a tourism boom.About 285 000 people visited the Caribbean country in 2016, up 74% over 2015, with Americans the third biggest group after Canadians and Cuban expats.Engage Cuba, a group lobbying for an end to the embargo, estimates that 10 000 US jobs in aviation and the cruise business already depend on Cuba.