France, Britain and Germany have said they could reactivate United Nations sanctions on Iran under a "snapback" mechanism if Tehran does not return to the table. The European states, along with the U.S., say Iran is working towards developing nuclear weapons. Iran says it is only interested in developing nuclear power.

The remarks by Supreme Leader Ayatollah Ali Khamenei comes as Tehran agrees to hold nuclear talks with European powers.

Iran's supreme leader said the current situation with the United States was "unsolvable," and that Tehran would never bow to pressure to obey Washington, amid a stand off with Western powers over its nuclear program,