Germany's Chancellor Angela Merkel says Iran must suspend uranium enrichment during talks on an international proposal to limit its nuclear program.

Ms. Merkel described the incentive offer drawn up by her country and the five permanent members of the U.N. Security Council - the United States, China, Russia, Britain and France - as comprehensive.

Angela Merkel (r) with Javier Solana

She discussed it Wednesday with European Union foreign policy chief Javier Solana. Solana delivered the offer to Iran Tuesday and says he is ready to return to Tehran for more talks if needed.

President Bush has welcomed Iran's initial response to the package, saying it appeared to be positive. Iran's chief nuclear negotiator, Ali Larijani, said the proposal has some positive steps but also contains "ambiguities." He promised that Iran will examine it in detail.

News reports quote diplomats as saying the incentives package would allow Iran to carry out small scale enrichment of uranium if it agrees to multinational nuclear talks.

Other incentives include international support in Tehran's effort to build a power plant running on nuclear energy. The United States would agree to drop trade sanctions, allowing Iran to buy spare parts for its aging fleet of American-made aircraft.

Throughout the long dispute with Tehran, the United States and Europe have contended that Iran is trying to develop nuclear weapons. Tehran denies the charge.