President Obama to Arrive in Havana Today at 4:50 pm

The visit, the first by a US president in 88 years, would have been unthinkable until Obama and Cuban President Raul Castro agreed in December 2014 to end an estrangement that began when the Cuban revolution overthrew a pro-American government in 1959.

Plain clothes police have blanketed the capital with security while public works crews have busily laid down asphalt in a city where drivers joke they must navigate "potholes with streets."

Welcome signs with images of Obama alongside Castro popped up in colonial Old Havana, where Obama will tour on Sunday afternoon shortly after landing.

Since rapprochement the two sides have restored diplomatic ties, signed commercial deals on telecommunications and scheduled airline service, and expanded cooperation on law enforcement and environmental protection.

Major differences remain, notably the 54-year-old economic embargo of Cuba. Obama has asked Congress to rescind it but has been blocked by the Republican leadership. Instead, Obama has used executive authority to loosen trade and travel restrictions.

Cuba also complains about the continued occupation of the naval base at Guantanamo Bay, which Obama has said is not up for discussion, and US support for dissidents and anti-communist radio and TV programs beamed into Cuba.

One person, who works as a nurse in Cuba said: "There are many years of mistrust and we are not going to change our system, our values. Although one must highlight that there are no longer invasions."

The highlights are likely to be Obama's speech on live Cuban television on Tuesday, when he will also meet dissidents and attend a baseball game between the Cuban national team and the Tampa Bay Rays.

"Times change and it's great that we have relations with the United States, even though they still impose the embargo," said a 28-year-old medical student. "But we can't blame all our problems on the US embargo."