On November 12, 1871, Sanjo and Saigo were entrusted with the duty of Rusu-naikaku (the acting cabinet while the heads of government are away), because a group of ambassadors, namely the ambassador who is the ambassador extraordinary and plenipotentiary Tomomi IWAKURA, vice ambassadors Takayoshi KIDO, Toshimichi OKUBO, Hirobumi ITO and Naoyoshi YAMAGUCHI went to Europe and the North America for revision of a treaty (Kunai-taijo (a post in the Imperial Household Ministry), and Shinpachi MURATA was one of the attendant).
明治4年（1871年）11月12日、三条・西郷らに留守内閣（留守政府）をまかせ、特命全権大使岩倉具視、副使木戸孝允・大久保利通・伊藤博文・山口尚芳ら外交使節団が条約改正のために横浜から欧米各国へ出発した（随員中に宮内大丞村田新八もいた）。