Iran's Foreign Ministry summoned Britain's ambassador to Tehran on Wednesday after Britain classified the Revolutionary Guards under the UK's 'Counter-State Threats' law, warning that the move 'will not go unanswered'.

The move came a day after Britain summoned Iran's charge d'affaires Ali Nasim Far in London over what the British government described as Iran's role in directing proxy groups to carry out attacks across Europe in recent months.

Britain on Monday classified the Revolutionary Guards and an affiliated group as an 'security threat' under new powers aimed at preventing other states from using proxies in activities such as surveillance and sabotage.

Iran's Foreign Ministry said Wednesday that 'following the unjustified measure taken by the British government in listing the Islamic Revolutionary Guard Corps under the Counter-State Threats law, Hugo Shorter, the British ambassador to Tehran, was summoned on Wednesday.'

The ministry stressed that the decision would face 'a similar and decisive Iranian response'.