"In our day no nation can live in isolation," the Pope said in an airport departure ceremony.

It followed earlier pleas for human rights to be respected within Cuba.

The Cuban President, Fidel Castro, said the Pope's visit showed Cuba had "nothing to hide" from the world.

"For every word you have said - even those I might disagree with - on behalf of all the Cuban people, Holy Father, I thank you," he said during a farewell speech.

Pope's appeal

The Pope urged other countries to embrace Cuba.

He said: "The Cuban people ... cannot be denied the contacts with other peoples necessary for economic, social and cultural development, especially when the imposed isolation strikes the population indiscriminately, making it ever more difficult for the weakest to enjoy the bare essentials of decent living, things such as food and education.

Side by side: the Pope and the president

"All should take practical steps to bring about changes in this regard."

With his own trip showing Cuba's return to its Catholic past after years of state-enforced atheism, the Pope suggested world leaders look for connections instead of differences.

"May nations, especially those which share the same Christian heritage and the same language, work effectively to extend the benefits of unity and harmony, to join efforts and overcome obstacles so that the Cuban people, as the active agents of their own history, may maintain international relations which promote the common good."

At the end of his five-day pilgrimage, the Pope also had strong words for President Castro.

Besides appealing for greater freedom, pluralism and religious tolerance, the Pope repeated his concern for political prisoners.

Members of the Vatican entourage said Cuban authorities had promised a "quick response" to the Pope's appeal earlier in the week for the release of about 200 prisoners, whom he believes are held because of anti-Castro views.

President Castro nevertheless congratulated the Pope for coming to "what some chose to call communism's last bulwark".

More than 300,000 people attended the Pope's farewell Mass

The Cuban leader acknowledged the risk some people had believed he was taking by inviting such an ideological opposite to his country.

"There were those who forebode apocalyptic events. Some even dreamed of them," he said.

This had not happened because Cuba was far more open than many outsiders realised, he added.