He is the first sitting US president to visit since the 1959 revolution, which heralded decades of hostility between the two countries.

Mr Obama said change would happen in Cuba and that Cuban President Raul Castro understood that.

The two leaders are meeting to talk about trade and are scheduled to hold a joint news conference.

For a US president to touch down at Jose Marti airport in Havana and be warmly greeted by Cuban's foreign minister was until recently unthinkable.

For decades, the US and Cuba were engaged in a bitter stand-off, triggered by the overthrow of US-backed Cuban dictator Fulgencio Batista by Communist leader Fidel Castro in 1959.

The US broke off diplomatic relations and imposed a trade embargo.

But President Obama undertook two years of secret talks which led to the announcement in December 2014 that the two countries would restore diplomatic relations.

Since then, there have been a series of symbolic moments, such as the first formal meeting of Presidents Obama and Castro at a regional summit in Panama and the opening of embassies in Havana and Washington DC.

Presidents Obama and Castro shook hands at the Palace of the Revolution in Havana ahead of their bilateral meeting on Monday.

They seemed visibly more relaxed than at their first official meeting at a regional summit in Panama just under a year ago and smiled broadly.

Following his arrival on Sunday, the first stop on President Obama's tour had been the newly re-opened US embassy in Havana, where he told staff it was "wonderful to be here".

But it was the visit to Havana's old town which brought home the long way US-Cuban relations have come since the thaw was announced 15 months ago.

While the plan to interact with Cubans in the streets was disrupted by a tropical storm, the image of the US president and his family braving the rain demonstrated to many Cubans his commitment to the new, warmer relationship.

President Obama is due to get down to the nitty gritty of politics in a face-to-face meeting with Cuban leader Raul Castro.

Their meeting at the Palace of the Revolution will be closely scrutinised for signs of how much practical progress has been made.

Ahead of the meeting, President Obama said he believed that "change is going to happen here and I think that Raul Castro understands that".

He also told US broadcaster ABC that he would be announcing that Google had made a deal with the Cuban authorities to expand Cuba's poor wi-fi and broadband access.

Many Cubans are hoping their economy will receive a further boost from further
openness and reforms as well as US investment.

Source:Bbc