Iran''s supreme leader charged Sunday that U.S. and its allies are behind the U.N. nuclear watchdog agency''s claim that Iran may be making nuclear bombs, despite its repeated denials.

The comments by Ayatollah Ali Khamenei, broadcast on state television Sunday, came 10 days after the International Atomic Energy Agency said it was concerned Iran may be working on nuclear weapons, echoing conclusions reached by the U.S. and several of its allies.

"Some IAEA reports and actions show that this international agency lacks independence," the television quoted Khamenei as saying. "The IAEA should not be influenced by the U.S. and some (other) countries because unilateral acts erode trust in the agency and the United Nations. It is also very bad for the prestige and reputation of these international bodies."

The language of the report — the first written by Yukiya Amano, who became IAEA head in December — appeared to be more directly critical of Iran''s refusal to cooperate with the IAEA than most of those of his predecessor, Mohamed ElBaradei.