In February 1873, he was dispatched to the Qing Dynasty capital Beijing as the envoy extraordinary and minister plenipotentiary to handle the Mudan Incident (refer to the Taiwan Expedition) which occurred two years earlier in Taiwan, and was successful in negotiating for the ratification of the Japan-Qing Treaty of Friendship and passing on a sovereign message of congratulations to the Qing emperor.
明治6年（1873年）2月には、前々年に台湾で起きた宮古島民殺害事件（→台湾出兵を参照）の処理交渉の特命全権公使として清の首都北京市へ派遣され、日清修好条規批准書の交換・同治帝成婚の賀を述べた国書の奉呈、および交渉にあたった。