Iran has not yet made a decision on withdrawing from the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), but any such move will be determined by Washington's conduct, a senior Iranian security official said on Saturday, 20 September 2026. The warning adds a new layer of urgency to already fraught nuclear diplomacy as US President Donald Trump prepares to address the United Nations General Assembly next week with Iran squarely in focus.

What the Security Chief Said

Mohsen Rezaei, Secretary of Iran's Supreme National Security Council, said in an interview that Tehran remains bound by a religious decree issued by the late Supreme Leader Ali Khamenei prohibiting the development of atomic weapons. However, he left the door open to a policy shift, stating, 'We do not know what will happen in the future.'

Rezaei outlined Iran's conditions for ending the war: a halt to hostilities on all fronts, the release of frozen Iranian assets, and the lifting of what he described as an anti-Iran naval blockade. He stressed it is in Washington's interest to accept these terms.

Mediation Efforts and Stalled Talks

Rezaei confirmed that consultations with Qatari and Pakistani mediators are ongoing, and that Iran has formally conveyed its conditions for negotiations with the United States through these channels. The mediation track has gained importance following a breakdown in direct progress.

On 18 June, the United States and Iran signed a memorandum of understanding (MoU) aimed at ending hostilities across all fronts. The agreement set a 60-day window — expiring on 17 August — for the two sides to reach a final accord. According to reports, that deadline passed without resolution, and a series of subsequent escalations has left the talks' fate deeply uncertain.

The Military Backdrop

The diplomatic impasse follows a sharp military escalation earlier this year. On 28 February, Israel and the United States launched joint strikes on Tehran and other Iranian cities. Iran responded with waves of missile and drone attacks targeting Israel and US military bases and assets across the region, and moved to tighten its grip on the Strait of Hormuz — a chokepoint through which a significant share of global oil supplies transit.

Trump's UN Diplomacy and Gulf Talks

President Trump is set to address the UN General Assembly on Tuesday before holding talks with leaders of the Gulf Cooperation Council (GCC) in New York. US officials confirmed Iran would be a central subject of discussion and warned of further consequences for entities doing business with Tehran. It remains unconfirmed whether Trump or other senior US representatives will hold direct talks with Iranian officials on the sidelines.

What Is at Stake

An Iranian withdrawal from the NPT would represent one of the most significant ruptures in the global nuclear non-proliferation architecture since North Korea exited the treaty in 2003. It would remove international legal constraints on Tehran's nuclear programme and almost certainly accelerate calls for military action. The threat, even if not yet acted upon, functions as leverage in an ongoing negotiation where Iran believes it holds critical cards — particularly control of the Strait of Hormuz.

All eyes now turn to the margins of the UN General Assembly, where back-channel contacts between Washington and Tehran will be closely watched for any signal of a diplomatic off-ramp.