Iran’s supreme leader has denounced a proposal by the United States aimed at curbing Tehran’s nuclear efforts and demanded that his country retains national independence amid reports of Washington offering to become involved in Tehran’s nuclear program.

Iran’s supreme leader has criticized an initial proposal from the United States in negotiations over Tehran’s rapidly advancing nuclear program.

Iran Supreme Leader Ayatollah Ali Khamenei Wednesday dismissed a U.S. proposal to halt Iranian uranium enrichment, appearing to reject a central U.S. demand in the nuclear program talks.