The head of the U.N. nuclear agency says Iran will eventually need security assurances from the United States in exchange for guarantees not to develop nuclear weapons.

Mohamed ElBaradei, the chief of the International Atomic Energy Agency, spoke to reporters in Paris Monday on the sidelines of a conference on the future of nuclear energy.

He said Washington will have to get involved when the European Union and Iran discuss security issues. Mr. ElBaradei says "regional security is not only a European affair."

Britain, France and Germany have offered Iran political and economic incentives if it abandons uranium enrichment activities capable of producing weapons grade material.

The United States, which accuses Iran of secretly trying to develop nuclear weapons, is now supporting the European effort by offering added incentives.

Iran insists its nuclear program is only for generating electricity.