U.S. Secretary of State Condoleezza Rice says Iran has made positive statements about an international incentives package aimed at curbing Tehran's sensitive nuclear activities.
But Rice, speaking to reporters in Washington, says the international community needs an answer.
Earlier Friday, Iranian President Mahmoud Ahmadinejad said the incentives package is a step forward and that Iran will carefully consider it. He said he will give a response in due time in line with his country's international interests.
The five permanent U.N. Security Council members, the U.S., Britain, France, China and Russia plus Germany approved the package, offered in exchange for Tehran suspending uranium enrichment and returning to talks on its nuclear program.
The incentives package was presented to Iranian officials last week. It includes a threat of penalties if Iran refuses to cooperate.
Details of the plan have not been made public.
In Brussels today, European Union leaders called on Iran to respond quickly and positively to the incentives offer. A summit declaration said any solution to the issue must address concerns about Iran's nuclear program while affirming Iran's right to the peaceful use of nuclear energy.
Recent reports by the International Atomic Energy Agency say Iran is continuing to obstruct inspections of its nuclear sites. The inspections could eliminate doubts about the true nature of Tehran's nuclear program.
The West suspects Iran is trying to develop nuclear weapons -- a charge Iran denies.
Some information for this report provided by AFP and Reuters.