European Union Development Commissioner Louis Michel urged Cuban President Fidel Castro to release imprisoned dissidents during a visit to Cuba to reopen talks between Brussels and Havana, an EU spokesman said. The four-hour meeting with the Cuban leader lasted into the early hours of Saturday, Michel's spokesman Amadeu Altafaj Tardio said. "Michel repeated to Castro the unvarying position of the EU in favor of the release of all political prisoners on the island," the spokesman said. "The meeting was cordial and very constructive," he said. Talks focused on EU relations with Cuba that were frozen two years ago after Castro ordered a crackdown on critics of his one-party Marxist state. The two men also discussed EU development aid to the Caribbean as well as Cuba's health and education assistance programs for neighboring islands, the spokesman said. Michel's visit is the most senior by an EU official since Cuba locked up 75 pro-democracy dissidents in March 2003, just days after the EU opened an embassy in Havana. Brussels suspended high-level visits and Cuba froze contacts with EU diplomats after they began inviting dissidents to their national day receptions in Havana.