At this point, the United States, which had declared and maintained its position of neutrality, supporting neither the new government nor the former bakufu, due to adept maneuvering by the new government announced that it would support the new government, and as a result the new government took possession of the then newest and most powerful ironclad warship, 'Azumakan,' renaming it 'Kotetsu'; the warship had been purchased by bakufu but hitherto not possessed by any political party because of the neutral status of the United States.
折りしも局外中立を宣言し新政府・旧幕いずれにも加担せずとの姿勢を貫いていた米国は新政府の巧みな切り崩しにより新政府支持を表明、幕府が買い付けたものの局外中立により所有が空中に浮いていた当時最新鋭の装甲軍艦「東艦」は新政府の手中に収まり「甲鉄」と命名された。