Britain, France, and Germany say measure will be imposed if no nuclear solution reached; Iranian lawmaker warns Tehran would leave Non-Proliferation Treaty

France, the U.K., and Germany are threatening to reinstate full U.N. sanctions on Iran if it doesn't come back to the nuclear negotiation table by the end of August.

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.