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.

Iranian, Egyptian and U.N. leaders have met to discuss Iran’s nuclear program after the U.N. nuclear watchdog agency said Iran is increasing its stockpile of uranium enriched to near weapons-grade levels.

The U.S. will reportedly allow Iran to enrich civilian-grade uranium in a proposed nuclear deal, marking a major concession from