Reince Priebus, who will serve as chief of staff in the incoming Trump administration, said “there’s going to have to be some movement” on the part of the Cuban government if it wished to have a relationship with the US.
It comes as workers in Havana made final preparations for a two-day memorial in the capital to Mr Castro, whose death on Friday at the age of 90 continued to spark celebratory scenes across the Straits of Florida in Miami.
Citing the need for religious freedom and open markets, Mr Priebus cautioned that Mr Trump was “absolutely” willing to perform a U-turn on president Barack Obama’s restoration of diplomatic relations between the two countries.
Following Mr Castro’s death, Mr Trump issued a statement expressing hope that Cuba would “move away from the horrors” towards a free future, but expanding on that yesterday, Mr Priebus made clear Havana would have to make significant progress.
“Repression, open markets, freedom of religion, political prisoners – these things need to change in order to have open and free relationships,” he explained.
“There’s going to have to be some movement from Cuba in order to have a relationship with the US. I think the president-elect has been very clear about this.”
In a subdued Havana, workers spent yesterday morning cleaning and erecting fencing and PA systems at the sprawling Revolution Plaza, where Mr Castro’s remains will lie in state today and tomorrow as part of a nine-day period of mourning declared by the Cuban government.
A statement published in Granma, the daily Communist Party newspaper, advised of a series of road closures across the city and said that people will be able to “pay tribute and sign a solemn oath to fulfil the concept of revolution” at the plaza.
Tens of thousands of islanders are expected to pay their respects to the former leader at the site, home to a monument to Cuba’s independence hero, Jose Marti, as well as a vast sculture of Ernesto “Che” Guevara.
Orlando Alvarez, 55, a jeweller who spent yesterday morning fishing on the Malecon boulevard, describedFidel Castro’s death as “a great sorrow” and predicted that “everyone” will visit the plaza over the coming 48 hours.
After a mass gathering in the plaza planned for tomorrow, Mr Castro’s remains will be taken to Santiago de Cuba, at the southeastern end of the island, reversing the journey that his rebels made in January 1959 when they seized power.
Mr Castro will be laid to rest on 4 December at the Santa Ifigenia cemetery in Santiago, the site of the tomb of Martí and other 19th century independence leaders.
With the memorial events due to get under way, Cuba’s most prominent dissident group yesterday called off its weekly protest march for the first time in 13 years.
The Ladies in White group, formed by wives and other relatives of activists jailed for their political opposition to the Castro regime, said it had called off its usual Sunday march “so that that the government does not take it as a provocation”.
The organisation’s leader, Berta Soler, said: “We respect the mourning of others and will not celebrate the death of any human being.”
In Miami’s Little Havana and Westchester districts, home to large Cuban-American populations, celebratory gatherings which began on Saturday spilled over into the early hours of yesterday morning.
Hundreds of Cuban Americans crowded streets in Hialeah and Little Havana to rejoice in Mr Castro’s death, with some waving the Cuban flag and banging on pots and pans. One enterprising Cuban immigrant, Arnaldo Bomnin, saw fit to celebrate in true capitalist style, offering discounts of up to £12,000 on cars for sale at his dealership.
“I was fortunate enough to make it to America and accomplish the American dream, and my hope is that one day Cubans will be able to experience the same freedoms there,” he explained.
It comes as the Cuban who as a boy survived a shipwreck and became the centre of an international custody battle in Florida in 2000 said Mr Castro will still be with Cubans even after his death.
Elian Gonzalez said in an interview with Cuban state television that it was “not right to talk about Fidel in the past tense… but rather that Fidel will be.” He said Mr Castro “is the present and the future.”
Mr Gonzalez explained that Mr Castro was a friend to his family at a difficult moment and made it possible for him to return to Cuba and be reunited with his father.
Mr Gonzalez was a young boy when he, his mother and others attempted the sea crossing between Cuba and Florida nearly two decades ago. His mother drowned on the voyage, but he survived and was taken to Florida.
A bitter dispute broke out between his relatives in the US, who wanted him to stay, and his father back home in Cuba.
Mr Castro made the issue a national cause and led huge demonstrations demanding the boy be returned to his father. US authorities eventually sent Gonzalez back.