▁started ▁non - stop ▁Shang hai - San ▁Francisco ▁service . ▁▁ 2 0 0 4 ▁agreement ▁A ▁new ▁agreement ▁was ▁signed ▁July ▁ 2 0 0 4 ▁ ▁The ▁agreement ▁allowed ▁each ▁country ' s ▁carri ers ▁to ▁serve ▁any ▁city ▁in ▁the ▁other ▁country . ▁In ▁practice , ▁service ▁between ▁the ▁two ▁countries ▁occurs ▁between ▁three ▁large ▁Chinese ▁cities ▁and ▁a ▁few ▁cities ▁in ▁the ▁U . S . ▁Prior ▁to ▁the ▁agreement , ▁Chinese ▁carri ers ▁were ▁limited ▁to ▁ 1 2 ▁U . S . ▁cities , ▁and ▁U . S . ▁passenger ▁carri ers ▁to ▁only ▁five ▁Chinese ▁cities . ▁The ▁agreement ▁permitted ▁un limited ▁code - sh aring ▁between ▁U . S . ▁and ▁Chinese ▁air lines , ▁which ▁had ▁previously ▁been ▁limited ▁to ▁certain ▁cities . ▁ ▁At ▁the ▁time ▁of ▁the ▁agreement , ▁there ▁were ▁plans ▁for ▁additional ▁negoti ations ▁to ▁begin ▁in ▁ 2 0 0 6 ▁which ▁led ▁to ▁another ▁agreement ▁in ▁ 2 0 0 7 . ▁ ▁The ▁ 2 0 0 4 ▁agreement ▁led ▁to ▁the ▁ 2 0 0 5 ▁expansion ▁of ▁fl ights ▁between ▁the ▁two ▁countries ▁as ▁well ▁as ▁new ▁service ▁by ▁North west ▁Airlines ▁from ▁Tokyo ▁to ▁Gu ang z hou , ▁which ▁began ▁on ▁November ▁ 1 , ▁ 2 0 0 4 , ▁operated ▁using ▁Bo eing ▁ 7 5 7 ▁aircraft . ▁( The ▁route ▁was ▁planned ▁to ▁be ▁res umed ▁on ▁July ▁ 6 , ▁ 2 0 1 1 , ▁by