Britain, Germany and France have told UN officials that snapback sanctions are on the table if Iran does not sit down to negotiate over its nuclear weaponry.

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.

France, the U.K. and Germany are threatening a return to measures from a decade ago if Iran doesn't agree to a deal over its nuclear program.