Iran’s Ambassador and Chargé d’Affaires to the United Nations Gholamhossein Darzi sent a letter, dated October 21, to UN Secretary-General Antonio Guterres and President of the UN Security Council Aglaia Balta, condemning the United States’ continued aggression against Iran through a naval blockade.

The full letter is as follows:

Upon instructions from my Government, and pursuant to our previous letters on the acts of aggression by the United States and the Israeli regime against the sovereignty and territorial integrity of the Islamic Republic of Iran, I wish to inform Your Excellency and the members of the Security Council of the continuing grave consequences of the persistent acts of aggression being committed by the United States of America against the Islamic Republic of Iran, which began on 28 February 2026, as well as of the subsequent imposition and continuation of an illegal blockade against Iran. These acts of aggression, compounded by the repeated and continuing threats by the President of the United States to destroy Iran’s infrastructure, constitute a grave threat to international peace and security and a flagrant violation of the Charter of the United Nations, particularly Article 2(4), as well as the peremptory norm of general international law (jus cogens) prohibiting aggression. Such threats and actions further endanger the civilian population and violate the fundamental obligations under international humanitarian law to protect civilians and civilian objects irrespective of the unlawful nature of the war of aggression imposed against the Iranian nation.

The United States has further continued and escalated its hostile acts by a campaign of economic coercion through the so-called “Operation Economic Outcast” and sweeping unlawful sanctions targeting Iran’s aviation sector and other vital sectors of its economy. These cumulative measures, in tandem with an aggressive maritime blockade, have compounded the grave consequences of the aggression and inflicted further harm on the civilian population amounting to collective punishment prohibited under international humanitarian law and international human rights law.

First, the continuation of the maritime blockade is neither an isolated measure nor a merely economic one. It forms part of the broader context of the original acts of aggression, the continuing use of military force, and the resulting violations of Iran’s sovereignty and territorial integrity. While the blockade has been accompanied by broader unlawful coercive measures, the legal implications of these actions are particularly serious and must be assessed in light of Article 2, paragraph 4, of the Charter of the United Nations, which prohibits the threat or use of force against the territorial integrity or political independence of any State. Article 3 (c) of the “Definition of Aggression” annexed to General Assembly resolution 3314 (XXIX) of 14 December 1974 expressly qualifies “the blockade of the ports or coasts of a State by the armed forces of another State” as an act of aggression. Such acts therefore give rise to Iran’s inherent right to self-defense under international law, which continues as long as the blockade is in force against Iranian territory.

Second, the United States cannot evade its international responsibility by replacing or supplementing direct military attacks with a sustained campaign of military interdiction and economic coercion. The law of State responsibility requires that the United States cease its internationally wrongful acts and make full reparation for the injury caused thereby, including all moral and material damage inflicted upon the Iranian nation as a result of the U.S. acts of aggression, as well as the direct targeting of civilians, including women and children, homes, schools, hospitals, other civilian objects and infrastructure. Where internationally wrongful conduct continues, the obligation to cease that conduct persists. The United States therefore bears international responsibility both for its initial acts of aggression and for its subsequent military actions, including the enforcement of the maritime blockade.

Third, the blockade and the associated restrictions have grave humanitarian implications extending far beyond military considerations. By impeding maritime commerce, restricting the movement of commercial vessels and disrupting access to essential supplies, these measures threaten the availability and affordability of food, medicines, medical equipment, fuel, agricultural inputs and other goods indispensable to civilian life. International humanitarian law imposes specific obligations concerning the protection of civilians, the prohibition of starvation of civilians as a method of warfare, and the facilitation of humanitarian relief subject to the applicable legal conditions. A military blockade cannot be used to impose collective punishment upon a civilian population or to deprive civilians of objects indispensable to their survival. In light of these obligations, the continued enforcement of the blockade constitutes a separate and distinct violation of international humanitarian law, compounding the unlawfulness of the original acts of aggression.

Fourth, the imposition of economic pressure through unlawful measures targeting Iran’s civil aviation sector and broader commercial and financial networks compounds these humanitarian and economic risks. Restrictions on airlines impede access to aircrafts, spare parts, equipment, maintenance, repair, inspection, and technical services indispensable to the safe operation of civil aircrafts, thereby exposing passengers and aviation personnel to risks and restricting the movement of millions of civilians. These measures also constitute a stark disregard for the binding Order of the International Court of Justice of 3 October 2018. The Court expressly recognized the potential impact of U.S. measures on civil aviation safety and the lives of its users, and ordered the United States to remove impediments to the free exportation to Iran of goods and services necessary for the safety of civil aviation. The systematic use of economic and financial measures to deliberately inflict severe and widespread hardship upon Iran’s civilian population for political coercion constitutes collective punishment and amounts to a crime against humanity, in flagrant violation of the Charter of the United Nations and fundamental rules of international law, including international human rights law.

Excellencies,

The Islamic Republic of Iran emphasizes that respect for sovereignty and territorial integrity, the prohibition of the use of force, and the peaceful settlement of international disputes are foundational principles of the international legal order upon which the United Nations was built. No State, irrespective of its military power or permanent membership in the Security Council, is entitled to disregard these obligations or to impose its will on another sovereign State through military coercion.

The continued enforcement of the maritime blockade, in the context of the war of aggression launched on 28 February 2026, risks perpetuating the unlawful use of force and normalizing violations of international law. It further undermines confidence in the authority of the Charter and in the capacity of the United Nations to uphold international law without selectivity or double standards. In this context, the Islamic Republic of Iran calls upon you, in the discharge of your responsibilities under the Charter, to:

Categorically reject and strongly condemn the continued acts of aggression by the United States against the Islamic Republic of Iran through maritime blockade as a flagrant violation of the Charter of the United Nations and international law, including the prohibition of the use of force, and the sovereignty and territorial integrity of the Islamic Republic of Iran;

Urge the United States to immediately cease its military aggression against Iran and lift the maritime blockade, respect Iran’s sovereignty and territorial integrity, and to comply fully with its obligations under the UN Charter and international law;

Recognize that the United States remains internationally responsible for its internationally wrongful acts, including its military aggression and any continuing violations of international law, and that the obligations to cease wrongful conduct and to make full reparation remain applicable in accordance with the law of State responsibility; and

Urge all Member States to refrain from recognizing, supporting, facilitating or implementing unilateral coercive measures by the United States which violate international law and the Charter of the United Nations, particularly measures that cause, or are foreseeably capable of causing, widespread humanitarian harm to civilian populations.

Accountability for aggression and other internationally wrongful acts is indispensable to the maintenance of international peace and security. The Islamic Republic of Iran will pursue all available legal avenues to ensure accountability, reparation and redress, and to hold those responsible to account for the consequences of these unlawful acts. The internationally wrongful acts of the United States entail its responsibility, including the obligation to make full reparation for the injury caused, encompassing restitution, compensation, and satisfaction in accordance with international law. This is without prejudice to any applicable individual criminal responsibility arising from the conduct of persons who have ordered, directed, facilitated or otherwise knowingly abetted the commission of war crimes against the Iranian nation during the recent wars of aggression imposed against Iran.

Iran will continue to exercise its inherent right of self-defence, consistent with Article 51 of the Charter, in response to any acts of aggression.

I should be grateful if you would have the present letter circulated as an official document of the Security Council.

Please accept, Excellencies, the assurances of my highest consideration.

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