moscow russia foreign ministry say friday ready talk unite state try keep landmark arm control treaty help end cold war alive moscow would comply obligations u.s. ministry refer intermediate-range nuclear force inf treaty sign 1987 ban soviet american short intermediate-range land-based nuclear conventional missiles statement publish mark 30th anniversary treaty sign soviet union ministry say moscow ready hold talk u.s. problems arise around treaty consider language ultimatums attempt pressure russia impose sanction unacceptable russia say ready talk u.s. try save arm pact