United Nations Secretary-General Antonio Guterres has expressed grave alarm over renewed overnight exchanges of fire between the United States and Iran, with his spokesperson warning that further escalation could have devastating consequences for civilians and the wider region.

UN's Stark Warning

Spokesperson Stephane Dujarric said on Wednesday that Guterres is “deeply alarmed by reports of civilian casualties, including in a strike that reportedly hit a wedding ceremony in Iran.” The Secretary-General has condemned all attacks against civilians and called on all parties to honour their obligations under international humanitarian law, including the principles of distinction, proportionality, and precaution.

“Further escalation … would have devastating consequences for civilians and for the wider region and beyond,” Dujarric said, noting that few countries in the region are immune from the spillover, with airspace and critical shipping routes already heavily impacted.

Casualties Reported Inside Iran

Iran’s Health Minister Mohammad-Reza Zafarghandi announced that 18 people were killed and 108 others wounded in overnight strikes by the United States, according to a statement published on the website of the Iranian president’s office. The figures have not been independently verified.

In a separate statement, Iran’s Foreign Ministry condemned what it described as the latest US “acts of aggression,” reiterating Iran’s determination to “decisively” defend its independence, national sovereignty, and territorial integrity.

Humanitarian System Under Strain

Dujarric underscored that the escalation in the Middle East has compounded an already dire humanitarian situation across the region. Humanitarian operations are reportedly overstretched and underfunded, and the renewed Gulf tensions risk pushing an already fragile system past its limits. This comes amid multiple overlapping crises that have strained UN relief capacity for months.

Call for Diplomacy

Guterres has urged both Washington and Tehran to return urgently to diplomacy, stating that a comprehensive and durable settlement can be achieved only through dialogue and negotiations. The appeal echoes earlier UN calls for restraint that have so far gone unheeded, marking a pattern of escalation and failed de-escalation efforts in the Gulf.

With civilian lives at stake and regional stability under acute pressure, the coming hours will be critical in determining whether the two sides heed the UN’s call for an immediate cessation of military action.