Washington has approved a request from former US president Mr Jimmy Carter to visit Cuba.
He will probably travel in mid-May, one of the sources said, confirming Carter had received permission for a licence to visit the Caribbean nation. There has been a US ban on travel by Americans to Cuba.
Mr Carter is a critic of long-standing US sanctions on Cuba and is deemed by President Mr Fidel Castro to be the friendliest of the ten US presidents to have held office during his 43-year rule.
While his visit is sure to bolster the anti-embargo lobby in the United States, the White House is probably calculating Mr Carter will press Castro on human rights and democracy issues, including the cases of some jailed dissidents.
Mr Carter, known for his monitoring of elections worldwide and humanitarian causes, would be the only former or sitting US president to travel to Cuba under Mr Castro, from whom he has a long-standing invitation to visit. He would be the most senior US figure on the communist-run island since the 1959 revolution.
"We want him to see our country, not so that he supports us or anything like that, indeed so that he may make all the criticisms he wants," Mr Castro said recently.
Dissidents in Cuba welcomed the visit, although they said they did not expect it to bring significant change in Cuban politics or in relation to the embargo, which Havana calls a blockade.