U.N. nuclear officials meet in Austria Monday to decide whether to help Iran complete a nuclear reactor near Tehran.
Iran says the Arak reactor will produce radioactive isotopes for medical uses. But plutonium, which can be used for atomic bombs, will be a by-product.
The debate over aid to the Arak reactor has become contentious, with western nations opposed and some developing nations in favor.
The U.S. ambassador to the atomic agency, Gregory Schulte says the U.S. opposes Iran's request.
Iran's envoy to the agency, Ali Asghar Soltanieh has accused the west of politicizing a technical issue.
News reports from Vienna quote anonymous diplomats who say the IAEA board is likely to refuse Iran's aid request by voting to postpone a decision.
Major powers accuse Iran of planning to build nuclear weapons, a charge Iran denies.
Iran says the Arak reactor is due to go online by 2009 . It says it will pursue the project whether or not the IAEA helps.
The IAEA board is considering this week hundreds of requests for technical aid from countries pursuing peaceful uses for nuclear power. The board routinely approves such requests.
But earlier this year, the IAEA suggested Iran should abandon the Arak project.
In August, Iran defied a United Nations deadline to cease enriching uranium. The UN Security Council is considering sanctions against Tehran.
Some information for this report was provided by AP and Reuters.