Cuban trip comes amid high anticipation and anxiety on the island.
President Barack Obama arrived in Cuba yesterday afternoon, a journey of only 145km from US shores that took more than half a century to complete.
Stepping off Air Force One under drizzling skies, the United States President held an umbrella over his wife, Michelle, as he was greeted by senior Cuban officials.
The Obamas, including the President's two daughters and his mother-in-law, were met on the tarmac by Bruno Rodriguez, Cuba's Foreign Minister, and Josefina Vidal, the head of the US section of Cuba's Foreign Ministry, as well as Jeffrey DeLaurentis, the senior US diplomat in Cuba. The official welcoming session was to take place today when Obama meets with Cuban President Raul Castro at the presidential palace.
Obama's trip here - the first by a sitting US president since 1928 - comes amid high anticipation and anxiety on the island within both the Communist Government and its political opposition. The Government hopes the two-day visit will allow it to reap benefits without ceding control, while dissidents on the island want it to speed the pace of change.
Obama hopes that reaching out to Cuba will encourage a generational evolution in one of the US's most bitter and long-standing adversaries. Just hours before his arrival, there were familiar signs that change will not come easily.
As morning Mass ended at Havana's Santa Rita church, several dozen women in white T-shirts - members of the Ladies in White group - filed out, assembled in rows and began walking silently down the street. A block away, hundreds of uniformed security personnel and plain-clothed men and women stood waiting.
They met at the corner in a melee of shouting and manhandling. The women in white went limp on the pavement, shouting "Freedom! Freedom! Freedom!" and throwing leaflets into the air. The security teams half-dragged, half-carried them to waiting buses.
All the cross-currents and contradictions of Cuba and its changing relationship with the US have been on display over the past two days. On Saturday, the US Coast Guard fished out 18 Cubans trying to reach Florida on homemade rafts. They reported that nine others had drowned on the journey.
Late Sunday, the Starwood hotel chain signed a mega-deal with the Cuban Government to manage three hotels on the island, the first US entrance into the tourist business here in more than 60 years.
Yesterday, Cubans crowded around their televisions to watch a hilarious phone conversation Obama taped with the island's best-known comedian.
Hours later, the Ladies in White were attacked.
"We want to see results" from the US opening, said Jose Daniel Ferrer, head of Cuba's largest dissident organisation, the Cuban Patriotic Union. "But Obama himself has said not to expect spectacular results ... and he has been exactly right."
Ferrer and several other dissident leaders have been invited to a private meeting with Obama tomorrow.
They agree that they are not expecting short-term liberalisation. But, they said, the combined weight of the US opening and the coming generational shift replacing Cuba's ageing leadership would inevitably bring down the system. "It's already easier to criticise Raul than it was Fidel," Ferrer said. "The next will be easier still." Raul Castro has said he will step down in 2018.
Far from yesterday's protests, Obama and his family first travelled to the Melia Habana hotel in the upscale neighbourhood of Miramar, where he met with the US Embassy staff.
Obama tried out his Spanish. "Que bola Cuba?" he tweeted on landing, using a particularly Cuban Spanish phrase meaning "What's up?"
The Obamas took a brief walking tour of Old Havana, the capital's 500-year-old historic quarter and a World Heritage Site.
As they visited the Plaza de Armas with umbrellas under a steady rain, crowds nearby chanted "USA! USA!"
Local resident Alberto Moreno, 35, a cook at a brewery, said earlier in the day that he thought Obama's visit would show that "Cuba is not the disaster that people in the United States think it is".