By Stephen Gibbs
BBC News, Havana
EU Development Commissioner Louis Michel has ended a visit to Cuba, optimistic that relations with the communist state will strengthen.
Europe had criticised Cuba over its imprisonment of 75 dissidents
The EU is Cuba's largest trading partner, but diplomatic relations have been frozen for almost two years.
Europe has criticised Cuba over its imprisonment of 75 dissidents and execution of three hijackers.
Earlier this year, Europe decided temporarily to lift its diplomatic sanctions for a six-month trial period.
Mr Michel said he had left Cuba far more positive than when he arrived.
The former Belgian foreign minister appeared particularly heartened by his meeting with President Fidel Castro.
The two men held what the commissioner described as a "deep conversation" until the early hours of Saturday morning.
Mr Michel also met leading Cuban dissidents and some of the relatives of those critics of Mr Castro who were imprisoned two years ago.
Human rights is the major sticking point between Europe and Cuba.
Europe has repeatedly called on Cuba to release all political prisoners.
Cuba says it does not hold any political prisoners, preferring to refer to dissidents on this island as mercenaries in the pay of the United States.
It would appear that Mr Michel did not receive any concrete commitment from Cuba regarding Europe's human rights concerns, but the commissioner said that at least Cuban officials had shown their willingness to discuss such matters.
Europe has given itself until June to see whether dialogue with Cuba proves a more effective policy than diplomatic sanctions.
Mr Michel said Cuba faced a clear choice between further global isolation and closer integration.
Although Cuba has expressed its desire to strengthen links with Europe, there are signs that its attention is elsewhere.
In recent speeches, Mr Castro has portrayed Venezuela and China as far more important partners.