Turkey has until next month to cancel a messy multibillion-dollar Russian arms deal or face harsh US penalties

During the first week of June, Turkey must cancel a multibillion-dollar deal with Russia and buy the U.S.-made Patriot missile defense system or face removal from Lockheed Martin's F-35 program, forfeiture of 100 promised F-35 jets, imposition of U.S. sanctions and potential blowback from NATO.