The UK, Germany and France believe that Iran is developing nuclear-capable ballistic missiles, according to a letter sent by the three nations to the UN.
The letter says ran tested a Shahab-3 missile variant that is equipped with a manoeuvrable re-entry vehicle. The missile could deliver a nuclear weapon.
They argued that the activity was in violation of a Security Council resolution.
Iran has since denied the accusations saying its nuclear programme is entirely peaceful. It argued that its ballistic missile programme does not violate the 2015 Iran nuclear deal.
The UN Security Council Resolution 2231 prohibits Iran from undertaking any activity related to ballistic missiles designed to be capable of delivering nuclear weapons. Such activities include launches using ballistic missile technology.