The US is “very open” to building a new relationship with Cuba, a senior American official has said.
However, Edward Alex Lee of the US state department stressed that any improvement should go hand-in-hand with more political freedom on the communist-run island.
Edward Alex Lee said the two countries had held “very constructive” talks on migration and other issues this week.
But he declined to give any details of what he called “substantial progress”.
Edward Alex Lee, who has been on an official visit to Cuba, added the two nations would seek to continue these rare negotiations.
“Despite our historically difficult relationship…we have been able to speak to each other in a respectful and thoughtful manner,” he told a news conference in Havana.
However, he added that the US wanted a “fundamental change” in the Cuban government’s attitude towards its own people.
Edward Alex Lee said the US and Cuba had held “very constructive” talks on migration and other issues
“We want to have that opening reflect – from the Cuban side – a respect for Cubans to express themselves freely, to be able to petition their government with grievances without the danger of arrest.”
Talks between the US and Cuba were suspended in 2011 but resumed last July.
The main focus of the latest talks was migration: discouraging Cubans from risking their lives at sea to reach the US, by ensuring that there were safe and legal alternatives.
The US and Cuba cut formal diplomatic ties more than five decades ago.
The talks, which took place in Havan, were also centered on other topics of mutual interest, including aviation safety, co-operation in counter-narcotics work, protocols on preparing for oil spills, search-and-rescue work, and renewing postal services between the two neighbors.
They came after the first handshake between President Barack Obama and his counterpart, Raul Castro, last month, at the memorial service for Nelson Mandela in South Africa.
Edward Alex Lee insisted however that the handshake was not pre-arranged, but reflected what he called the “innate graciousness” of Barack Obama.
The dialogue between the Cold War foes was cut after Cuba sentenced a US citizen, Alan Gross, to 15 years in prison for smuggling illegal satellite equipment into the country.
Edward Alex Lee confirmed that he had visited Alan Gross in prison, adding that the US was “deeply concerned” about his wellbeing. He expressed hope that the Cuban government would free Alan Gross, arguing the contractor had simply been providing internet access for Cuba’s small Jewish community.
Cuba’s President Raul Castro has called for “civilized relations” with the US, saying the two countries should respect their differences.
Raul Castro said the US should drop its demand for regime change on the communist-run island.
That would allow both sides to continue work on improving relations, the president said.
Raul Castro’s comments follow a public handshake with President Barack Obama at the memorial ceremony for Nelson Mandela in South Africa earlier this month.
In a rare public speech, Raul Castro said Cuban and American officials had met several times over the last year to discuss practical matters, such as immigration and the re-establishment of a postal service.
That shows that relations can be civilized, Raul Castro explained.
President Raul Castro has called for “civilized relations” with the US
However, he warned: “If we really want to make progress in bilateral relations, we have to learn to respect each other’s differences and get used to living peacefully with them. Otherwise, no. We are ready for another 55 years like the last.”
The US broke off relations with in 1961 after the revolution and maintains an economic embargo against the island.
“We do not ask the United States to change its political and social system, nor do we agree to negotiate over ours,” Raul Castro told legislators at the closing session of the parliament in the capital, Havana.
Raul Castro, 82, took over from his brother, Fidel, in 2006. Fidel Castro had serious health problems and was never able to come back to power. Two years later, he resigned and transferred control permanently to Raul Castro.
He has since carried out a programme of economic reforms, which has helped efforts for relations with the US to be improved.
But critics say the pace of change has been too slow.
“The reform process in Cuba cannot be rushed or it will lead to failure,” Raul Castro warned.
Among the most recent changes announced by Raul Castro is the end of restrictions on private individuals to buy new and second hand cars.
Anyone with enough money will be allowed to order the vehicles from a government dealer.
Until now, only those who were given a previous government authorization were allowed to buy cars in Cuba.
The White House said President Barack Obama and Cuba’s President Raul Castro’s handshake at Nelson Mandela’s memorial service was unplanned.
White House aide Ben Rhodes told reporters the two exchanged no words more substantive than a greeting.
The Cuban government said the gesture may show the “beginning of the end of the US aggressions”.
The US broke off diplomatic ties with Cuba in 1961 as Fidel Castro aligned with the Soviet Union in the Cold War.
On Tuesday, after the handshake, a White House official said the Obama administration still had grave concerns about human rights violations in Cuba, Reuters reported.
Republicans on Capitol Hill were quick to condemn the gesture, with one Republican congresswoman chiding the move during a unrelated hearing on Tuesday.
The White House said President Barack Obama and Cuba’s President Raul Castro’s handshake at Nelson Mandela’s memorial service was unplanned
“Sometimes a handshake is just a handshake, but when the leader of the free world shakes the bloody hand of a ruthless dictator like Raul Castro, it becomes a propaganda coup for the tyrant,” Florida Congresswoman Ileana Ros-Lehtinen, who is known for her opposition to the Castro government, told Secretary of State John Kerry.
“Could you please tell the Cuban people living under that repressive regime that, a handshake notwithstanding, the US policy toward the cruel and sadistic Cuban dictatorship has not weakened.”
The last US president to shake a Cuban leader’s hand was President Bill Clinton, who greeted President Fidel Castro, Raul’s brother and predecessor, at a 2000 UN General Assembly meeting.
Under President Barack Obama, the US has eased restrictions on Cuban-Americans travelling to the island and on remittances between family members across the two countries.
But the gradual thaw has been disrupted by the detention in Cuba of a US contractor.
Alan Gross, 64, was arrested four years ago while on a project to provide internet access to Cuba’s small Jewish community.
On the fourth anniversary of his arrest, Alan Gross wrote to Barack Obama to say he feared the US government had “abandoned” him, and asked the US president to intervene personally to help win his release.