A spokesman for British Prime Minister Boris Johnson responded Monday to an announcement by Iran Sunday that Tehran would no longer adhere to any limits placed on its nuclear program by the 2015 nuclear deal.

The spokesman told reporters that Iran's announcement was "extremely concerning", and said the British government was discussing the matter with other signatories of the nuclear deal.

“Iran’s announcement is clearly extremely concerning. It is in everyone’s interests that the deal remains in place. It makes the world safer by taking the prospect of a nuclear-armed Iran firmly off the table,” the spokesman said.

“We have always said the nuclear deal is a reciprocal deal, and in light of Iran’s announcement we are urgently speaking to partners about next steps.”