Trump warns Iran faces 'violence like people haven't seen before' if nuclear deal fails / Iran stands firm on nuclear rights, foreign minister says / Trump offers Iran choice: Drop nuclear weapons or face 'maximum pressure' / Trump says Iran "cannot have a nuclear weapon" but adds he wants to "make a deal" / Iran tells US it doesn't want nuclear weapon -- Witkoff / China insists on political solution to Iran nuclear issue -- foreign minister / Diplomatic opening on Iran nuclear issue / Israel still intends to attack Iran's nuclear sites / White House: 'Ultimate' US goal is to prevent Iran from getting nuclear weapon / Russia considers strikes on Iran's nuclear facilities unacceptable -- diplomat