Britain is not part of the war against Iran and remains committed to resolving tensions through diplomacy, UK Foreign Secretary Ed Miliband told his Iranian counterpart Abbas Araghchi during a telephone conversation, according to Iran’s Foreign Ministry.

The call came amid heightened tensions in the Middle East and followed Iran’s warning to Britain to reconsider policies that could facilitate US military operations against Tehran, including allowing the use of British military bases.

According to a statement issued by Iran’s Foreign Ministry on Saturday, Araghchi said any cooperation with the United States or other countries involved in military action against Iran was “unacceptable.”

He argued that under international law and the UN definition of aggression, a country that allows its territory or facilities to be used for an unlawful attack on another state could also be considered an aggressor, adding that the targeted country would have the legitimate right to self-defence.

Iran criticises UK policies

During the conversation, Araghchi criticised Britain’s decision to designate Iran’s Islamic Revolutionary Guard Corps (IRGC) as a national security threat and condemned what he described as British support for US and Israeli military actions against Iran.

The Iranian foreign minister said London’s recent stance toward Tehran was “unfair” and required reconsideration, maintaining that US and Israeli actions against Iran were the primary cause of the current regional crisis.

Araghchi also said Iran had participated in negotiations in good faith and had agreed to a memorandum on a ceasefire on June 18, but claimed the United States failed to honour its commitments and prevented the agreement from being implemented.

Hormuz and diplomacy discussed

The Iranian foreign minister reaffirmed Tehran’s commitment to establishing a practical mechanism with Oman to manage maritime navigation through the Strait of Hormuz.

He warned that interference by any third party could further complicate the situation in the strategically important waterway.

For his part, Miliband stressed that Britain was not participating in the conflict against Iran and believed diplomacy remained the only viable path to resolving disputes.

He also emphasised the importance of maintaining diplomatic engagement with Tehran, saying continued dialogue could help improve bilateral relations and reduce tensions across the region.

The latest exchange comes as relations between Tehran and London remain strained following Britain’s tougher stance on Iran.

The UK government has declared the IRGC a national security threat and announced stricter penalties for individuals found assisting the organisation.

Iran has repeatedly accused the United States and its allies of escalating regional instability.

At the same time, Western governments continue to express concerns over Tehran’s regional activities, missile programme and support for armed groups in the Middle East.