Reuters - Britain is extremely concerned about Iran’s announcement on Wednesday that it is scaling back curbs to its nuclear programme, Prime Minister Theresa May’s spokesman said, urging Tehran not to take escalatory steps.

Iran announced steps that stop short of violating its 2015 deal with world powers for now, but threatened more action if countries did not shield it from U.S. sanctions.

“We are extremely concerned about this announcement and urge Iran to continue to meet its commitments under the deal and not to take escalatory steps,” the spokesman told reporters.

“This deal is a crucial agreement which makes the world safer and we will ensure it remains in place for as long as Iran upholds these commitments.”

Reporting by Elizabeth Piper, Writing by Kylie MacLellan' editing by Kate Holton