Iran's president has proposed new ways out of the ongoing crisis over his country's nuclear programs, said an Iranian official.

In a letter, the first letter from an Iranian leader to a U.S. president in 27 years, President Mahmoud Ahmadinejad has offered President George W. Bush "new solutions" to their differences, said government spokesman Gholam-Hossein Elham.

The letter was sent via the Swiss Embassy.

Washington has had no diplomatic relations with Tehran since 1979, when the U.S. Embassy was stormed. The leaders of the two countries have not directly corresponded in that time.

The United States is leading a group of Western countries, including the European Union, in trying to stop Iran from enriching uranium.

Iran, which announced last week its uranium enrichment program was progressing well, insists its nuclear intentions are peaceful, that it only wants to generate electricity.

But other countries worry that Tehran wants to build nuclear weapons.