Iran is poised to reject a U.S. proposal to end a decades-old nuclear dispute, an Iranian diplomat said on Monday, dismissing it as a "non-starter" that fails to address Tehran's interests or soften Washington's stance on uranium enrichment.

Iran is currently reviewing a formal U.S. nuclear deal proposal as both sides remain deeply divided over uranium enrichment limits and sanctions relief.

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 preliminary U.S. proposal came as a confidential U.N. report described an Iranian initiative that had multiplied Tehran’s stockpile of near-bomb-grade uranium.

Iran carried out secret nuclear activities with material not declared to the UN nuclear watchdog at three locations that have long been under investigation, the watchdog said in a wide-ranging, confidential report to member states seen by Reuters.

Iran lashes out at Austria after a report claims Tehran has an advanced nuclear weapons program, sparking diplomatic tensions and calls for explanations.

Iran's foreign ministry and the Iranian nuclear agency rejected the report, calling it "politically motivated" in a joint statement.

Iran warned it won’t strike a nuclear deal with the US unless Washington gives assurances that any agreement will include sanctions removal.

Iran is poised to reject a U.S. proposal to end a decades-long nuclear dispute, an Iranian diplomat said on Monday, slamming it as a "non-starter" that fails to address Tehran's interests and leaves Washington's stance on uranium enrichment unchanged.

Iranian, Egyptian and U.N. leaders met in Cairo on Monday to discuss Iran's nuclear program after a report from the U.N. nuclear watchdog agency said that Iran is further increasing its stockpile of uranium enriched to near weapons-grade levels.

An Axios report revealed the United States will allow Iran to continue limited uranium enrichement under certain conditions as part of its nuclear deal with the country.