Iran ? From the deck of Iran’s new guided-missile destroyer, Supreme Leader Ayatollah Ali Khamenei denied Friday that Tehran was seeking nuclear weapons and criticized the U.S. military presence in the Gulf.

His comments came as international concern rose over Tehran’s nuclear ambitions a day after the International Atomic Energy Agency said it may currently be working on making a nuclear warhead, suggesting for the first time that the Islamic Republic had either resumed such work or never stopped at the time U.S. intelligence thought it did.

Russia, which has been on the fence about whether to impose new U.N. sanctions against Iran, said it was “very alarmed” over Tehran’s failure to prove its nuclear program is peaceful.

Khamenei said his country was not developing nuclear weapons because Islam forbids weapons of mass destruction.