Jimmy Carter on Sunday became the first U.S. president to go to Cuba since Fidel Castro's 1959 revolution.

Shortly after Carter's plane touched down about 10:45 a.m., the world was treated to the unique spectacle of a former American president shaking hands with the Cuban dictator, who was dressed in a grey suit instead of his trademark green fatigues. 

"It is no secret that for almost a century there have not been optimal relations between the two states," Castro told Carter in his brief remarks. "However, I wish to state that in the four years of your tenure as president, you had the courage to make efforts to change the course of those relations. That is why those of us who were witnesses to that attitude see you with respect.

"Our country receives you and your delegation with sincere hospitality," Castro added.

The setting was of remarkable friendliness between the two nations, who are officially enemies. Near the two leaders was a wooden podium with microphones, flanked by the Cuban and American flags. And after Castro escorted Carter and his wife, Rosalynn, down a red carpet leading to the podium, they all stood at attention while a military band played the Cuban national anthem, the Bayamesa, followed by the Star Spangled Banner.

Waiting nearby were two black Soviet-made Zil limousines, a gift to Cuba from then-Soviet leader Leonid I. Brezhnev in the mid-1970s and the vehicles used for only the most distinguished of guests.

Castro told Carter he was welcome to talk to whomever he wants "even if they do not share our endeavors" β€” an obvious reference to the human rights activists with whom the former American president is expected to meet.

"You will have free and complete access β€” together with any specialists of your choosing β€”to that or any other of our most prestigious scientific research centers, some of which have been recently accused, just a few days before your visit, of producing biological weapons," said Castro, who has vigorously denied the accusations.

In Spanish, the former American president said he looked forward to meeting with Castro, as well as "representatives of religious groups and others to examine the ideas that are important for Rosalyn and me," including peace, human rights, democracy and the easing of human suffering.

"We understand that we have differences in some of these themes, but we appreciate the opportunity to try identifying some common points."

Although Carter has emphasized that this is a private visit and that he will not be negotiating with the Cuban government, people on all sides of the debate are pressuring him to push their agendas.

The White House and Cuban exiles want Carter, who has made a post-presidential career out of monitoring elections in developing democracies, to talk bluntly with his host about human rights and democracy. Exile groups also hope Carter will bring up Project Varela, a campaign by Cuban activists to force a referendum asking voters if they want liberties such as freedom of speech and the right to start their own businesses. The organizers delivered their petition signatures to the legislature Friday.

On the other hand, Cuban officials and a growing number of Americans who oppose U.S. sanctions hope Carter will publicly condemn the U.S. trade embargo.

"To emphasize dialogue and engagement is the best means to advance U.S. interests in Cuba and to promote political and economic reform on the island β€” something the 40-year-old embargo has utterly failed to achieve," said Sally Grooms Cowal, a former U.S. diplomat who is president of the Cuba Policy Foundation.

Carter has long been on record as opposing the embargo. Earlier this year, he said increasing trade and visits by Americans to Cuba could spread understanding of the advantages of freedom.

As president from 1977-81, Carter helped re-establish diplomatic missions in both countries and negotiated the release of thousands of political prisoners. He also made it possible for Cuban exiles to visit their relatives on the island and, for a short time, for other Americans to travel here freely.

But the trade embargo is still in place after four decades and relations are as chilly as they've ever been. The Bush administration has hardened the U.S. stance toward Havana, promising not to ease trade sanctions until Cuba holds free elections and releases political prisoners.

Calvin Coolidge was the last American head of state to go to Cuba, in 1928.

Wayne Smith, the chief U.S. diplomat to Havana during the Carter administration, said he didn't expect "any miracles."

But "Carter cannot achieve less than (President) Bush has, which has been zero," he added. 

Castro and Carter will have plenty of time to talk, especially during two dinners that Castro plans for Sunday and Wednesday.

Carter is traveling with his wife and a small group of executives and staff from the couple's nonprofit Carter Center in Atlanta.

They will tour renovation projects in historic Old Havana; an agricultural cooperative; a medical-research center and several schools. Carter is to make a live televised address to the Cuban people Tuesday.

Carter's staff has said he will meet with members of human-rights and religious groups Thursday. The delegation is to depart Cuba around midday Friday.

The Associated Press contributed to this report.