BERLIN -- The top diplomats of Britain, France, and Germany threatened to reimpose sanctions on Iran as an end-of-the-month deadline nears for the country to resume negotiations with the West over its nuclear program and cooperation with the United Nations nuclear watchdog.

France, Germany and the UK were signatories to the 2015 Joint Comprehensive Plan of Action (JCPOA) alongside the United States, China, Russia and the European Union. The accord required Iran to limit its uranium enrichment in exchange for sanctions relief.

France, Germany and Britain have written to the United Nations to say they are ready to reinstate sanctions on Iran if it does not return to negotiations with the international community over its nuclear programme.