World leaders have welcomed a historic move by the US to end more than 50 years of hostility towards Cuba and restore diplomatic relations.
Pope Francis joined leaders from Latin America and Europe in praising the "historic" deal which saw the release of prisoners from both countries.
But dozens of dissident Cubans oppose the move, which some Republicans have labelled a "retreat" by the US.
US-Cuban ties have been frozen since the early 1960s.
President Obama said the "rigid and outdated policy" of isolating Cuba since then had clearly failed and that it was time for a new approach.
Mr Castro, meanwhile, has urged the US to ends its trade embargo, which has been in place since the Cuba turned to communism more than 50 years ago. Read more here.
Discuss: How should Cuba and the US move forward after normalising their relations?