U.S. President Barack Obama was set to announce a major shift in policy toward Cuba on Wednesday, which would include the opening of an embassy in Havana and the start of talks to normalize relations, officials and media said.

The shift in policy, set to be one of the biggest changes in decades of animosity between communist-ruled Cuba and the United States, was heralded by Cuba's release of American aid worker Alan Gross after five years in prison in a reported prisoner exchange with Havana.

Obama was due to make a statement at noon (1700 GMT) on Cuba, the White House said, and a U.S. official said he would announce a shift in Cuba policy. Cuban President Raul Castro was also set to make a statement at that time.