shuttle diplomacy
noun [ U ] uk/ˈʃʌt.əl dɪˌpləʊ.mə.si/ us/ˈʃʌt̬.əl dɪˌploʊ.mə.si/
穿梭外交
discussions between two or more countries, in which someone travels between the different countries, talking to the governments involved, carrying messages, and suggesting ways of dealing with problems