People walk past a painting of late revolutionary hero Ernesto "Che" Guevara in Havana Wednesday. (Ueslei Marcelino/Reuters)

The first family will travel with President Obama on Sunday to Cuba, where he will deliver a speech to the Cuban people that the administration expects will be broadcast nationwide, meet with political dissidents, entrepreneurs and President Raul Castro, and attend a U.S.-Cuba baseball game.

Outlining the trip to reporters, Ben Rhodes, Obama’s deputy national security adviser, said that the Tuesday morning speech would be “as important as anything else he’s doing” on the island.

Held at the recently renovated Gran Teatro Alicia Alonso in central Havana, it “will address the very complicated history between our two countries . . . [and] make clear what his vision is for the future of relations between the United States and Cuba, and the future that we would wish for the Cuban people.”

While Obama will not shy away from discussing human rights, “the difference here is that in the past, because of certain U.S. policies, the message that was delivered in that regard either overtly or implicitly suggested that the United States was seeking to pursue regime change . . . or the United States thought we could dictate the direction of Cuba,” Rhodes said.

Obama will make clear, he said, “that the United States is not a hostile nation seeking regime change, that in fact we can’t be blamed for challenges in Cuba, and that . . . we are there as a source of support for the Cuban people.”

People surf the Internet at a public Wi-Fi hotspot in downtown Havana. (Desmond Boylan/AP)

One of Obama’s goals on the trip is to press the Cuban government to move more quickly to take advantage of trade and other openings that he has brought about through regulatory changes in U.S. law, even as he has been unable to persuade the Republican-controlled Congress to lift the 56-year-old embargo against Cuba.

Despite the U.S. changes — and a steady stream of U.S. business and government delegations to Cuba over the past 15 months since the normalization of ties began — few actual deals have been signed. Cuba objects to the continuing embargo, and is short of money to purchase U.S. technology and products, even within the small range that is newly permitted.

Rhodes said the administration wants “very much to make the process of normalization irreversible” beyond Obama’s term in office, and will propose “steps that the Cuban government can take going forward to further open up space for the Cuban people.”

Obama will be accompanied by three Cabinet secretaries, at least three dozen members of Congress and a large business delegation. After leaving Cuba late Tuesday, he will spend two days in Argentina, where the administration is trying to build a relationship with newly elected President Mauricio Macri after years of estrangement under previous governments.

But most attention has been focused on Cuba, where Obama will be the first U.S. president to set foot in more than 80 years. Critics charge that the president has broken his own pledge not to visit the island until human rights are improved.

“The president has negotiated a deal with the Castros, and I understand his desire to make this his legacy issue,” Sen. Robert Menendez (D-N.J.) said on the Senate floor Wednesday. “But there is still a fundamental issue of freedom and democracy at stake that goes to the underlying atmosphere in Cuba and whether or not the Cuban people — still repressed and still imprisoned — will benefit from the president’s legacy, or will it be the Castro regime that reaps the benefits.”

Menendez cited rising rates of detention and harassment of political dissidents, including the reported arrest this week of Carlos Oliva, head of the youth front of the opposition Patriotic Union of Cuba, three days after he returned to the island after meeting with Rhodes in Miami.

People make their way along Neptuno Street at dusk in downtown Havana Wednesday. U.S. President Barack Obama will travel to Cuba on March 20. (Desmond Boylan/AP)