Iran must “immediately stop and reverse” actions which breached the terms of its nuclear deal, the UK Government has demanded.
Tehran has announced it will raise its enrichment of uranium, breaking another limit of its 2015 agreement with world powers.
Government spokesman Ali Rabiei told a news conference that Iran will go beyond the limit of 3.67% enrichment and that the new percentage “will be based on our needs”.
Iran made the decision a year after US President Donald Trump unilaterally withdrew the US from the deal, putting its future in doubt.
The UK, France, German, Russia and China remain signed up to the Joint Comprehensive Plan of Action (JCPOA) deal with Iran, which is aimed at preventing Tehran acquiring nuclear weapons.
A Foreign Office spokesman said: “Iran has broken the terms of the JCPOA, following its announcement that it will start uranium enrichment above the 3.67% limit agreed in the nuclear deal.
“While the UK remains fully committed to the deal, Iran must immediately stop and reverse all activities inconsistent with its obligations.
“We are co-ordinating with other JCPOA participants regarding the next steps under the terms of the deal, including a joint commission.”
Tehran’s decision came less than a week after it acknowledged breaking the deal’s 300 kilogram limit on its low-enriched uranium stockpile.
The JCPOA’s difficulties come against a backdrop of increase tensions in the Gulf following an attack on two oil tankers which the UK and US have blamed on Iran and the downing of a US drone.