US President Barack Obama embarked on a historic trip to Cuba on Sunday, more than a year after Washington reset its foreign policy towards the island following decades of Cold War animosity that almost led to a nuclear war.
The three-day trip - the first by a US president in 88 years - was unthinkable until Obama and Cuban President Raul Castro agreed in December 2014 to re-establish diplomatic ties.
The US broke off ties with the communist nation of 11 million when Cuban revolutionaries led by Fidel Castro ousted a pro-American government in 1959.
On Sunday evening, Foreign Minister Bruno Rodriguez met Obama at the Jose Marti Airport after Air Force One touched down in Havana, 145 kilometres from the southern US state of Florida.
Cuban police, meanwhile, broke up the regular march of a leading dissident group, the Ladies in White, detaining about 50 people hours before Obama arrived. About 200 protesters have been briefly arrested in the past few days.
Obama will meet government critics on Tuesday. The leader of the Ladies in White, Berta Soler, has been invited. She was among those detained on Sunday.
The Cuban government dismisses dissidents as mercenaries seeking to destabilise the country.
Plainclothes police blanketed the capital, Havana, with security while public works crews laid down asphalt to fill potholes, as the island nation prepared a red-carpet welcome for Obama and his family.
Cuba: History is on Obama's side
Little progress on the main issues is expected when Obama and Castro meet on Monday.
Instead, the highlights are likely to be Obama's speech on live Cuban television on Tuesday when he will also attend a baseball game between the Cuban national team and the Tampa Bay Rays.
Welcome signs with images of Obama alongside Castro popped up in colonial Old Havana, where the president and his family will tour later on Sunday.
Since rapprochement, the two sides have restored diplomatic ties, signed commercial deals on telecommunications, and scheduled airline services.
Major differences remain, however, notably the 54-year-old economic embargo of Cuba, which it calls a blockade. Obama has asked Congress to rescind it but has been blocked by the Republican leadership.
Instead, he has used executive authority to loosen trade and travel restrictions to advance his outreach to Cuba, one of his top foreign policy priorities along with the Iran nuclear deal.
IN PICTURES: Changing face of Cuba
Obama's critics at home accuse him of making too many concessions for too little in return from the Cuban government, and of using his trip to take a premature "victory lap" to polish his foreign policy legacy.
|The US and Cuba: Obsession
But Obama's more practical goal is to do everything he can in his final 10 months in office to make his Cuba policy changes irreversible, even if a Republican wins the White House in November's election.
Cuba also complains about the continued occupation of the naval base at Guantanamo Bay, which Obama has said is not up for discussion, as well as US support for dissidents and anti-communist radio and TV programmes beamed into Cuba.
Cuba has defended its universal healthcare and education as human rights and criticises the US record on race relations and the Guantanamo Bay military prison.
The Americans, in turn, criticise one-party rule and repression of political opponents.
On the eve of Obama's visit, a US hospitality company announced its first business deal in Cuba since the 1959 revolution, while online lodging service Airbnb said it would now allow travellers from around the world to book stays in private homes in the island nation known for its beautiful beaches and heritage buildings.
|Flags of the United States and Cuba were displayed in the capital Havana [EPA]