Gates described the deal as "between the Afghan government and the Italians," but said he was concerned because it allows the released Taliban to resume attacks.
U.S. State Department spokesman Sean McCormack said the United States does not negotiate with terrorists and advises that others not negotiate with them either.
Italian Foreign Minister Massimo D'Alema earlier said he was not sorry to have saved the life of journalist Daniele Mastrogiacomo.
Officials said D'Alema discussed the case in a telephone call with U.S. Secretary of State Condoleezza Rice.
RFE/RL Afghanistan Report
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