Iran's top leader claims the country is immune to Western sanctions over its controversial nuclear program and has been able to make technological advancements despite the punitive measures.

Supreme Leader Ayatollah Ali Khamenei's remarks on state TV Wednesday were meant to shrug off the latest EU ban on Iranian oil sales that was imposed to pressure Tehran to halt uranium enrichment, which is a potential pathway to nuclear weapons.

The embargo went into effect July 1, adding to U.S.-led sanctions on Iranian crude and further cutting into exports of OPEC's second-largest producer.

The U.S. sanctions prohibit the world's banks from completing oil transactions with Iranian banks and further complicate Iran's ability to conduct international commerce.

The U.S. and its allies accuse Iran of seeking nuclear weapons, a charge Tehran denies.