Miami ? A former adviser to Fidel Castro’s brother has defected, apparently becoming the highest-ranking Cuban official to seek political asylum in the United States.

Alcibiades Hidalgo, 56, was once Raul Castro’s chief of staff. He also served as Cuba’s ambassador to the United Nations from 1992 to 1993 and was a member of the Central Committee of the island nation’s Communist Party. He fell out of favor with the government in the mid-1990s, he said.

Hidalgo told the El Nuevo Herald, a Spanish-language newspaper in Miami, that although he once believed in Fidel Castro’s communist system, he now sees it as a failure.

“Socialism hasn’t worked,” Hidalgo said in the interview published this week. “There isn’t a real economic program that will take the island out of its subsistence way of life. Life in Cuba is extraordinarily difficult.”