The deterioration of President Fidel Castro's health has been accompanied by the rise of hardline elements to key positions in Cuba, leaving no possibility for democratic reformers to surface, a senior State Department official said Wednesday.

"With Fidel Castro still alive, the regime has become more orthodox," said Thomas Shannon, who heads the State Department's Western Hemisphere affairs bureau. "It is hard to say what position it will take post-Fidel."

In the meantime, he said, "the success of the succession depends on the absolute control of the state."

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For now, he added, potential reformers have been lying low, awaiting a more favorable climate to make their move. Once Castro dies, Cuban authorities will have a choice between "deepening repression" or a policy of greater openness to the world, Shannon added.

He said the United States has no way of corroborating persistent reports of Castro's deteriorating health, noting that the subject is treated as a state secret in Cuba.

The clearest sign that Castro's health is faltering occurred 10 days ago when he failed to make an appearance at delayed 80th birthday celebrations held in his honor, Shannon said. His actual birthday was in August, two weeks after Castro surrendered power to his brother, Raul, following intestinal surgery.

The brother is his designated successor but many analysts believe a power struggle is inevitable.

Cuban officials have said repeatedly that Castro's health continues to improve. But there have been no photographs of him in two months, and at the time he looked extremely frail.

As Cuban officials see it, the system Castro created will survive him. But Shannon expressed doubt that a successor can match the traits that have enabled Fidel Castro to survive in power for almost 48 years.

"There is nobody like Fidel," Shannon said, citing his "revolutionary legitimacy," charisma, political skills and ruthlessness.

Almost 25 years have passed since the United States and Cuba last held political discussions, and Shannon said he does not foresee any until Cuba has a leader committed to democratic change.

He brushed aside a proposal by Raul Castro several weeks ago for a dialogue between the two countries.

Shannon said release of political prisoners is a necessary but insufficient ingredient for a resumption of a political dialogue. Other prerequisites are a pathway to elections, guarantees for the protection of human rights and permission for independent organizations to be established, he said.

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