moscow kremlin say monday talk saudi arabia moscow supply riyadh advance s-400 air defense missile systems go well far despite talk possible u.s.-saudi arm deal russian president vladimir putin host saudi arabia king salman talk kremlin last week saudi arabia say sign memorandum understand purchase s-400s day late pentagon say u.s. state department approve possible sale thaad anti-missile defense system saudi arabia estimate cost 15 billion ask whether possible u.s. deal riyadh might affect russian arrangement kremlin spokesman dmitry peskov conference call reporters say talk progress well speak say peskov contact implement contract positive good preliminary result maria vorobyova official russian government agency deal military technical cooperation cite early monday say firm agreement reach saudi arabia s-400s agreement reach kingdom saudi arabia deliver s-400 air defense system anti-tank kornet-em rocket systems tos-1a multiple rocket launcher systems ags-30 automate grenade launchers kalashnikov ak-103 assault rifle ria news agency cite say russia also sign contract last week saudi produce ak-103 rifle license along ammunition saudi arabia longstanding u.s. ally middle east arm deal moscow cause disquiet washington ask fear saudi arabia could use s-400 system iran russian ally peskov say moscow decision offer missiles riyadh aim third party military technical cooperation moscow riyadh absolutely self-contained target third countries region regions world say peskov therefore confident cooperation worry anyone kremlin say s-400 missile talk saudi arabia track