Iran's Foreign Ministry has condemned the new British government's decision to allow the United States to use its military bases and facilities to prepare for and facilitate unlawful military attacks against the Iranian people.

In a statement, the ministry said the decision is in clear violation of the fundamental principles and rules of the United Nations Charter and international law, adding that it would be regarded as an act of aggression against Iran under Article 3(f) of United Nations General Assembly Resolution 3314, which defines aggression.

The statement said British officials made the decision while being fully aware that the U.S. military attacks against Iran—launched with the participation of the occupying and genocidal Israeli regime and continuing to this day—constitute a clear act of aggression and a flagrant violation of the fundamental principles of the UN Charter and peremptory norms of international law.

The ministry further stressed that "any participation in or cooperation with the preparation and execution of these unlawful attacks amounts to complicity in the crime of aggression and war crimes."

According to the statement, the United Kingdom, in its national capacity and as a permanent member of the UN Security Council, chose to side with the aggressors instead of condemning the U.S. and Israeli military aggression and war crimes against the country. The ministry said London had reduced its position to that of a partner in a brutal war against the Iranian people, undermining the UK's claims of supporting the rule of law, human rights, and international peace and security.

The statement also argued that the British ruling party's support for the unlawful U.S.-Israeli war against Iran not only violates international legal obligations to respect Iran's national sovereignty and territorial integrity, but also recalls the United Kingdom's historical atrocities and interventions against the Iranian people. It cited the 1953 coup, Britain's subsequent comprehensive support for Saddam Hussein during the eight-year Iran-Iraq War, the imposition illegal sanctions under the pretext of Iran's nuclear program, following the United States in the snapback sanctions mechanism, and the "absurd" designation of the Islamic Revolutionary Guard Corps.

The ministry concluded by reaffirming that the Islamic Republic of Iran is determined to defend its national sovereignty, territorial integrity, national interests, and security against any foreign aggression. It warned that any party participating in any form of military aggression against Iran would bear responsibility for the consequences of its decision.