France, Britain and Germany have threatened to trigger the “snapback mechanism” that automatically reimposes all United Nations sanctions on Iran over its nuclear program.

Iran faces a renewal of UN-mandated sanctions within weeks unless it returns to negotiations on the future of its nuclear program and allows international inspections of its facilities.

If Iran's nuclear program is no longer under credible international monitoring, it poses a serious risk of proliferation. Tehran insists it does not seek nuclear weapons in response to Western and the International Atomic Energy Agency's (IAEA) accusations,