Iran's supreme leader, Ayatollah Ali Khamenei said Tuesday his country will continue with its controversial nuclear program, but rejected nuclear weapons.

The country's supreme leader also said U.S. President George W. Bush and his advisers are acting erratically and sound mentally ill.

"Sometimes they threaten, sometimes they order assassinations ... and sometimes they ask for help — it's like mad people staggering to and fro," he said.

Khamenei, who has final say in all matters in Iran, spoke at a ceremony Tuesday honoring the founder of the Islamic Republic, Ayatollah Ruhollah Khomeini.

"Iran is after the peaceful use of nuclear energy and we will strongly pursue and reach it despite the envy of our enemies," he said.

"No wise nation is interested in making a nuclear weapon," since it is not logical and cannot be used, added.

Earlier on Monday, U.N. atomic watchdog chief Mohamed ElBaradei asked for more clarity from Iran about its nuclear program since it had not provided requested access to documents and individuals.

Khamenei also warned against nuclear terrorism, saying that one day "world terrorists could attain nuclear weapons and take peace away from all the people in the world."

The Iranian leader also accused the U.S. of using nuclear energy for maintain its dominance over other nations in the world.

"Americans, who are leading the opposition to Iran's nuclear energy, are signing nuclear agreements with less advanced countries," which would result in their dependency on the U.S., he said.

Khamenei did not elaborate, but the United States has concluded bilateral nuclear cooperation deals with the United Arab Emirates, Bahrain and Saudi Arabia.

The U.S and its allies accuse Iran of having secret nuclear weapon program. Tehran dismisses the charge saying its nuclear activities are only for peaceful purposes.