washington president barack obama still grapple historic decision whether lift u.s. arm embargo vietnam days travel white house say thursday signal human right concern could stick point support grow within u.s. administration capitol hill fully remove least ease ban weapons sales bolster tie former wartime enemies washington hanoi counter rise china obama also face stiff opposition quarter end embargo something vietnam long seek would sweep away one last major vestiges vietnam war era obama make first trip begin monday would also anger beijing condemn obama partial lift ban 2014 interference region u.s. deliberations come amid increase tensions dispute south china sea beijing demand end u.s. surveillance area thursday two fighter jet carry pentagon say unsafe intercept u.s. military reconnaissance aircraft ben rhodes obama deputy national security adviser say administration yet finalize decision lift three-decade-old embargo dodge question even whether announcement might make soon subject discussion vietnamese tell reporters preview obama trip say president would explain think country communist leadership something obviously look context broad relationship white house officials make clear final decision would link part vietnam human right situation concern remain especially among right advocate u.s. lawmakers government heavy-handedness toward political opponents treatment workers also worry washington lose leverage give arm embargo without secure concessions reform still obama aid mindful failure satisfy vietnam call rescind ban could inject sour note visit mean open new chapter security economic relations vietnamese officials suspicious unite state seek undermine one-party rule want demonstrate visit significant upgrade relationship unite state vietnam partner many issue even significant areas difference rhodes say obama make stop hanoi ho chi minh city meet vietnam new president tran dai quang well new prime minister nguyen xuan phuc communist party general secretary nguyen phu trong also meet dissidents deliver speech vietnamese people rhodes say u.s. officials say matter decision weapons ban expect obama visit yield tangible step boost military cooperation washington look increase port visit u.s. warships possibly include access strategic port cam ranh bay hold naval exercise accord person close u.s. think subject story refiles add drop letter right lead obama grapple vietnam arm ban human right eve trip