Cuban officials select 57-year-old First Vice President Miguel Mario Diaz-Canel Bermudez as the sole candidate to succeed Raul Castro as president of Cuba

HAVANA: Cuba on Wednesday selected 57-year-old First Vice President Miguel Mario Diaz-Canel Bermudez as sole candidate to succeed Raul Castro as president of Cuba, the centerpiece of an effort to ensure that the country's single-party system outlasts the aging revolutionaries who created it.

The virtually certain unanimous approval of the National Assembly will install someone from outside the Castro family in the country's highest government office for the first time in nearly six decades.

The 86-year-old Castro will remain head of the Communist Party, designated by the constitution as "the superior guiding force of society and the state." As a result, Castro is almost certain to remain the most powerful person in Cuba for the time being. His departure from the presidency is nonetheless a symbolically charged moment for a country accustomed to 60 years of absolute rule first by revolutionary leader Fidel Castro and, for the last decade, his younger brother.

Nominated as new first vice president was Salvador Valdes Mesa, a 72-year-old Afro-Cuban former union official who has held a long series of high posts in the Cuban government. The government's official Candidacy Commission also nominated another five vice presidents of the Council of State, Cuba's highest government body. Only one of the five, 85-year-old Ramiro Valdez, was among the revolutionaries who fought with the Castros in the eastern Sierra Maestra mountains.

Facing biological reality, Raul Castro is working to ensure a smooth transition from him and his small group of former guerrillas to a new generation that can maintain the government's grip on power in the face of economic stagnation, an aging population and waning revolutionary fervor among Cuban youth attuned more to global consumer culture than the anti-capitalist, nationalist messaging of the state-run media.

That media went into overdrive Wednesday with a single message: Cuba's system is continuing in the face of change. Commentators on state television and online offered lengthy explanations of why Cuba's single-party politics and socialist economy are superior to multi-party democracy and free markets, and assured Cubans that no fundamental changes were occurring, despite some new faces at the top.

"It falls on our generation to give continuity to the revolutionary process," said assembly member Jorge Luis Torres, a municipal councilman from central Artemisa province who appeared to be in his 40s. "We're a generation born after the revolution, whose responsibility is driving the destiny of the nation."

Most Cubans know their first vice president as an unremarkable speaker who initially assumed a public profile so low it was virtually nonexistent. Until March, Diaz-Canel had said nothing to the Cuban people about the type of president he would be. The white-haired, generally unsmiling Diaz-Canel had been seen at greatest length in a leaked video of a Communist Party meeting where he somberly pledged to shutter some independent media and labeled some European embassies as outposts of foreign subversion.

That image has begun to change slightly this year as Diaz-Canel stepped into the moderate limelight offered by Cuba's Soviet-style state media. With his public comments in March, many Cubans got a glimpse of him as a flesh-pressing local politician, an image familiar to residents of the central province where he was born and spent nine years in a role akin to a governor.

Castro entered the National Assembly just after 9 a.m. accompanied by a broadly smiling Diaz-Canel.

The 604 assembly members were sworn in — a 605th was absent — then voted for the president and vice president of the legislative body itself. The result of the votes for president and vice presidents and other national leaders is expected to be officially announced Thursday, the anniversary of the U.S.-backed Bay of Pigs invasion defeated by Cuban forces in 1961.

As in Cuba's legislative elections, all of the leaders being voted in on Wednesday are selected by a government-appointed commission. Ballots offer only the option of approving or disapproving the official candidate. Candidates generally receive more than 90 percent of the votes in their favor.

Fidel Castro was prime minister and president from 1959 until he fell ill in 2006. Although Osvaldo Dorticos was president of Cuba during Fidel Castro's time as prime minister, he was considered a figurehead beside the man who led Cuba's revolution, forged its single-party socialist system and ruled by fiat.