The Iranian Foreign Ministry on Tuesday condemned Britain's "hostile" decision to designate Iran's Islamic Revolution Guard Corps (IRGC) as a national security threat, calling it "unjustified, irresponsible, and in violation of international law."

In a statement, the ministry said the IRGC is an integral part of Iran's armed forces, responsible for defending the country's territorial integrity and national sovereignty and security alongside the regular army.

It called Britain's decision a "ridiculous and provocative act" that contravenes the UN Charter, particularly given the current situation in West Asia, which it blamed on U.S. and Israeli actions.

It added that Iran reserves all its rights under international law to take countermeasures and warned that Britain would bear responsibility for the "destructive" political, legal and diplomatic consequences of its decision.

The British government announced Monday that it was moving to designate the IRGC and two other organizations as national security threats.

If approved by parliament, they will become the first organizations designated under the National Security (State Threats) Act 2026, according to a written statement by British Security Minister Angela Eagle.

The designation would make it a criminal offense to support or assist the organizations in activities linked to Britain, or knowingly receive a material benefit from them. Certain offenses could carry a maximum sentence of life imprisonment.

The IRGC has already been sanctioned in its entirety by Britain.