US President Barack Obama began his first full day in Cuba with wreath laying ahead of an official meeting with President Raul Castro in which Obama will press the Cuban leader for economic and democratic reforms while hearing complaints about continued US economic sanctions.

This will be the fourth Obama and Castro meeting and is likely to be their most substantial. It will be held at the Palace of the Revolution, where Castro and his predecessor, older brother Fidel Castro, led Cuba's resistance to US pressure going back decades.

A US presidential visit to the inner sanctum of Cuban power would have been unthinkable before Obama and Raul Castro's rapprochement 15 months ago, when they agreed to end a Cold War-era dispute that lasted five decades and continued even after the collapse of the Soviet Union.

The two leaders have deep differences to discuss as they attempt to rebuild the bilateral relationship.

Obama is under pressure from critics at home to push Castro's Communist government to allow dissent from political opponents and further open its Soviet-style command economy.