Iran designated Britain's Royal Navy and Royal Air Force as "terrorist" organizations and its foreign intelligence agency MI6 as a "hostile group" on Sunday, according to the Iranian Foreign Ministry.
In a statement carried by state-run news agency IRNA, the ministry said the move came in response to London's "malicious" actions, particularly its designation of Iran's Islamic Revolutionary Guard Corps (IRGC) as a "terrorist organization."
The ministry said the decision was taken under a resolution by Iran's Supreme National Security Council and followed the UK's designation of the IRGC under the State Threats Act 2026 on July 13.
Tehran also accused London of participating in the US-Israeli war against Iran by providing access to military and logistical bases and facilities under British jurisdiction.
Tensions in the Middle East have remained high since the US and Israel launched attacks against Iran on Feb. 28, triggering Iranian retaliation across the region.
Despite subsequent diplomatic efforts and a memorandum signed by Washington and Tehran in June, tensions have persisted over security arrangements and navigation through the Strait of Hormuz.
