HAVANA — In his first hour as Cuba’s new head of state, Miguel Díaz-Canel sought to make one thing clear: Raúl Castro may no longer be president, but he is still the power to be reckoned with in this island nation.

“Raúl . . . will be key to the process of making the most important decisions on the future of the nation,” Díaz-Canel, 57, said Thursday on the floor of Cuba’s National Assembly after he was formally named head of state.

The National Assembly’s procedure ended Castro rule here after nearly 60 years, shifting power toward a younger generation, born after Cuba’s revolution. Yet everything about the transition Thursday suggested a path ahead of supremely cautious change with a heavy dose of continuity.

Castro, who took over from his older brother, Fidel Castro, in 2008, will remain the head of Cuba’s powerful Communist Party. Insiders say he may leave Havana, moving to the southeastern city of Santiago, not far from the family farm where he and his brother grew up, and which Fidel Castro later nationalized. He died in 2016 at age 90.

The Post spoke with Cubans and Cuban-Americans in Havana and Miami about Cuban President Raul Castro’s resignation in April. (Joyce Lee, Sarah Parnass, Julia Galiano-Rios/The Washington Post)

But any move to the countryside should not be seen as Raúl Castro fading into the background.

On Thursday, he followed Díaz-Canel’s stiff, serious speech with a far longer, more animated and sometimes playful discourse that stole the day’s thunder. Seeming supremely comfortable, he often digressed, tackling issues from diversity to Cuban history to climate change.

He openly described the choice of Díaz-Canel as a handpicked succession, calling him the only one of a group of politicians in their 50s who had risen to the occasion of top leadership

“His election is not by chance,” Castro said. “It was planned by us in group, and we decided that he’s the best option in our opinion.”

Castro promised to stay on as head of the Communist Party until his term ends in 2021, a post he said he hoped Díaz-Canel would assume afterward.

“When I’m gone, and that’s in the future,” Castro said, “he will take over as first secretary of the Communist Party, if he does a good job. That’s how it’s been planned.”

Signaling reforms to come, however, Castro said that in July, Cuba would create a committee with the aim of revamping its constitution. The socialist character of Cuba, he said, would not change. But he acknowledged that “we thought, at this point, we would have advanced more” on the road toward greater economic reforms.

“We haven’t renounced the pursuit of private-sector work,” he said.

Though highly symbolic for Cuba, the narrative of the end of the Castro era was largely played down here by state media, which sought to portray the transition as an exercise in continuity.

Díaz-Canel’s name was put forward Wednesday as the sole candidate to head Cuba’s Council of State, a post that effectively serves as the presidency. On Thursday, officials announced the results of the vote: 603 to 1 backing his nomination as Cuba’s new leader. Díaz-Canel, a consensus builder, is almost sure to make decisions in concert with the country’s Communist brain trust.

At a time when a thaw in U.S.-Cuban relations under President Barack Obama has turned to winter under President Trump, Díaz-Canel opened no immediate window in his speech for improved relations.

Instead, he paid homage to the Castro brothers, Raúl and Fidel, as well as “the historic generation” of older revolutionaries who have run Cuba for decades. He promised to bring “continuity to the Cuban revolution,” and talked of cautious change, but always in the context of Cuban socialism.

“There is no room for those who aspire to a capitalist restoration,” he said. “We will defend the revolution and continue to perfect socialism.”

Always the more reform-minded of the brothers, Raúl Castro leaves the presidency having set in motion an important period of political and economic changes to Cuba’s one-party state — including the introduction of term limits, the lifting of travel restrictions for Cubans and legalization of the sale of real estate.

But he left just as much undone, and Díaz-Canel is now poised to inherit significant problems. He must confront the task, for instance, of converting Cuba’s outdated and cumbersome two-currency system into a one-currency system.

Last year, Cuba also put the brakes on the issuing of new licenses for small private businesses, mostly restaurants, taxi companies and Airbnb operations aimed at the tourism industry. Cuban officials argued that they needed to ensure such businesses were paying taxes and obeying the law.

But some observers said rank-and-file party officials also resented that upstart entrepreneurs were obtaining a higher standard of living than they could. It will be up to Díaz-Canel to find a balance between those in Cuba who are reluctant to embrace economic change and those who are clamoring for it.

“My guess is that he will follow the path of economic reform, because he has to,” said John Caulfield, chief of the U.S. Interests Section in Havana from 2011 to 2014. “If he doesn’t, he runs the risk of failure, of growing discontent. And he may have a honeymoon period where, if he wants to, he can get things done.”