The IAEA chief is expected to hold talks with U.S. Secretary of State Condoleezza Rice, National Security Adviser Stephen Hadley, intelligence chief John Negroponte and top U.S. senators on Tuesday and Wednesday.

During the talks, ElBaradei is likely to urge U.S. officials to consider security assurances for Iran in order to defuse the crisis over Tehran's nuclear program, diplomats said.

ElBaradei is likely to stress the need for a far-reaching accord covering trade, security and diplomatic issues to reach a durable solution to the nuclear stand-off, the diplomats added.

The United States has accused Tehran of using its atomic energy program as a cover for developing atomic weapons.

But Iran has said its uranium enrichment efforts are only aimed at making fuel for nuclear power generation, and that it has the right to conducting such activities in line with the Non-Proliferation Treaty.

A draft proposal by the EU trio of Britain, France and Germany gives green light for Iran to build light water reactors and set up a nuclear fuel bank that would guarantee the country access to reactor fuel but not the sensitive fuel cycle technology.

But the EU trio has said that if Tehran did not accept the proposal, sanctions should follow, which could include an arms embargo and other political and economic measures.