Barack Obama on Sunday became the first US president in 88 years to visit Cuba, touching down in Havana for a landmark trip aimed at ending decades of Cold War animosity.
"Que bola Cuba?" Obama tweeted on landing, using Cuban slang to ask what's going on. "Just touched down here, looking forward to meeting and hearing directly from the Cuban people."
Moments later, a smiling Obama emerged from Air Force One with First Lady Michelle and their two daughters Sasha and Malia, clutching umbrellas to shield themselves from a warm afternoon rain shower.
He was greeted on the tarmac by Cuban Foreign Minister Bruno Rodriguez, before loading into his bulky limousine, nicknamed "the beast".
Obama is not only the first sitting US president since Fidel Castro's guerrillas overthrew the US-backed government of Fulgencio Batista in 1959, but the first since President Calvin Coolidge in 1928 to visit Cuba.
Seeking to leave a historic foreign policy mark in his final year in office, Obama toured the newly reopened US embassy and old town Havana, and will hold talks with Cuban President Raul Castro today and attend a baseball game before leaving on Tuesday.
For Cubans dreaming of escaping isolation and reinvigorating their threadbare economy, the visit has created huge excitement.
"A president of the United States in Cuba arriving in Havana on his Air Force One," wrote popular Cuban writer Leonardo Padura on the Cafefuerte blog. "Never in my dreams or nightmares could we have imagined that we'd see such a thing."
For days, Havana's old town has been crawling with painters sprucing up the picturesque neighbourhood and the Stars and Stripes - long the enemy flag - has appeared over numerous buildings.
Early on Sunday, cleaners swept the narrow, cobbled streets where Obama was due to stroll later and police, especially plainclothes, were out in large numbers.
But minutes before Obama took off for Cuba, police in Havana arrested dozens of people from a banned group demanding greater human rights, AFP reporters said.
The protesters were from the Ladies in White, formed by wives of former political prisoners. Police bundled them into vehicles outside a church where they attempt to hold protests almost every Sunday.
Republicans and some human rights activists have criticized Obama for dealing with Castro, given the lack of political, media and economic freedom in a country where the Communist Party retains tight control.
White House deputy national security adviser Ben Rhodes insists that the subject will be brought up. Obama will meet members of Cuba's beleaguered opposition and give a speech at the National Theater carried live on Cuban television.