Tourists pass the U.S. Embassy in Havana on Feb. 18, 2016. (Alexandre Meneghini/Reuters)

In the months since President Obama announced his historic deal to normalize relations with Cuba, the communist government of Raúl Castro has taken only the most modest steps toward less authoritarian rule.

Nonetheless, the White House announced Thursday that the president will visit Cuba in March in an attempt to bolster the controversial diplomatic deal — and to spur the sort of political change that the Cuban government has not yet embraced.

Speaking to reporters Thursday, White House deputy national security adviser Ben Rhodes said the administration’s “objective here is to do as much as we can with the time we have remaining to make this an irreversible policy.”

Obama has made clear that his outreach is focused more on the Cuban people and less on the government. Cuban officials, while eager for American investment, are hoping to reap the economic benefits of a normalization policy while giving up as little political control as possible.

The Cuban government continues to crack down on political dissent, and administration officials acknowledge that Havana has not done enough to allow for freedom of expression. Rhodes said Thursday that the president would meet with dissidents during next month’s visit.

Cuba’s minister of foreign trade and commerce, Rodrigo Malmierca Díaz, left, meets the U.S. secretary of state, John F. Kerry, on Feb. 18, 2016, in Washington. (Ismael Francisco/AP)

The independent Cuban Commission for Human Rights and National Reconciliation reported last month that 1,414 Cubans had been detained for political reasons in January, one of the highest monthly figures in recent decades. Of those, the commission reported, 56 peaceful members of the opposition were physically attacked.

Nearly all of the arrests occurred during regular Sunday-morning opposition marches to Catholic churches and resulted in brief detentions of four to six hours. The Sunday marches have become a principal avenue of protest for opposition groups.

In a December interview with Yahoo News, Obama said he would need to see progress on human rights before planning a trip. “If, in fact, I with confidence can say that we’re seeing some progress in the liberty and freedom and possibilities of ordinary Cubans, I’d love to use a visit as a way of highlighting that progress,” he said. “If we’re going backwards, then there’s not much reason for me to be there.”

The president has said repeatedly the way to rebuild the U.S.-Cuba relationship is by people-to-people engagement. First lady Michelle Obama will accompany the president on the visit, which will be March 21 and 22, and the White House is billing it as a chance to engage regular Cubans. Afterward, the Obamas will travel to Argentina for two days, where they will meet with recently elected President Mauricio Macri.

“We want links between Cubans and Americans,” Rhodes said, “and the links between our businesses and the engagement between our countries to gain such momentum that there’s an inevitability to the opening that is taking place.”

Carlos Alzugaray, a retired Cuban diplomat who also is a member of the Communist Party, used language similar to Rhodes’s to describe his government’s motivations for hosting Obama.

Alzugaray said the visit will “consolidate the strategy of both governments to bring about a series of fundamental changes,” making them “as irreversible as possible.”

Cuban President Raúl Castro is seen at the Revolution Palace in Havana on Feb. 18, 2016. (Enrique De La Osa/Reuters)

The Cuban government has made some efforts to expand communications and opportunities for U.S. businesses on the island in the past year. Havana has opened dozens of WiFi hotspots around the country and forged roaming agreements between the state telecommunications service and U.S. companies Verizon and Sprint. Havana also has authorized direct banking relationships with U.S. financial institutions and lines of U.S. credit for private Cuban businesses on the island, according to the U.S.-Cuba Trade and Economic Council.

A small U.S. tractor manufacturer, Cleber, has received Cuban approval and an unprecedented U.S. Treasury license to establish a manufacturing plant on the island to produce up to 1,000 tractors annually.

The decision for Obama to go this early in the year — even as the Cuban government continues to routinely arrest and detain dissidents — drew swift and sharp rebukes from some of the top Republicans vying to be their party’s presidential nominee as well as from several GOP figures on Capitol Hill.

Sen. Ted Cruz (Tex.), whose father was born in Cuba, tweeted in response to the news: “My family has seen firsthand the evil and oppression in Cuba. The President should be advocating for a free Cuba!”

In a letter to Obama, Sen. Marco Rubio (Fla.), whose parents were born in Cuba, accused Obama of rewarding the Cuban government’s tyranny.

“I urge you to reconsider visiting Cuba and instead insist that the Castro regime finally make some serious concessions that have so far not been prioritized in negotiations,” Rubio wrote.

But administration officials, as well as some independent experts, said the United States would be more likely to achieve meaningful policy agreements by conducting face-to-face talks earlier in the year rather than later.

American University government professor William LeoGrande said there are “about two dozen different conversations underway” between the two governments, on issues including global health, law enforcement and counternarcotics efforts.

“A trip like this gives impetus to all of those dialogues, so the earlier you do the trip, the more chance you have of reaching agreements on a whole host of additional issues,” LeoGrande said.

And many experts see this as a unique opportunity.

Dan Restrepo, who served as Obama’s primary adviser on Latin America during the president’s first term, noted that in the past, when Democratic presidents sought a rapprochement, Cuban authorities always derailed the process. When Jimmy Carter tried it, Fidel Castro authorized a mass emigration out of Mariel Harbor in 1980. Bill Clinton had to deal with the shooting down of two Brothers to the Rescue planes by the Cuban air force in 1996, and the 2009 arrest of Alan Gross, a contractor for the U.S. Agency for International Development, froze Obama’s initial gestures toward a reset with Cuba.

“Every time you got close to engagement, they backed away,” Restrepo said.

For the government of 84-year-old Raúl Castro, who has said he will step down in 2018, the trip comes at a delicate time. He or his brother Fidel, 89, have ruled the island since the 1959 overthrow of U.S.-backed strongman Fulgencio Batista, and whoever succeeds them in power will have little chance of commanding their type of unchallenged authority.

Cuba’s economy is under new strains from the financial turmoil in Venezuela, the island’s biggest benefactor. Cubans are leaving the island at the highest levels in decades. The benefits of Raúl Castro’s cautious economic liberalization have been unevenly distributed and disappointing to many.

Obama may arrive with what could appear to Cubans to be an extended hand and a clear path for them out of their worst problems.

“I think this is very difficult trip for Cuban government,” said Arturo López-Levy, a former analyst for Cuban intelligence services and now a lecturer at the University of Texas in the Rio Grande Valley. “The type of trip Obama is planning presents a political challenge. Whatever positive things Raúl Castro has said about Obama, he is still seen in the official narrative as the head of the American Empire. Yet he is just as popular on the island as any politician in the world, let alone in Cuba.”

If Obama’s message is that Cuban nationalism can coexist with the island’s “return to the international liberal world order,” López-Levy said, it “presents an acrobatic challenge to a government that has based its legitimacy on what happened in 1959 and the logic of a nationalist revolt.”

Obama’s trip could have the effect of further raising Cubans’ expectations for better living standards and more freedoms, López-Levy said, and will almost certainly boost the case of reformers within the Communist Party who want a faster pace of change.

Obama on Thursday seemed excited about the visit. “It’ll be fun when we go,” he said.

Miroff reported from Medellin, Colombia. Karen DeYoung contributed to this report.