During his 1881 world tour, Kalākaua held a secret meeting with Emperor Meiji and proposed to unite the two nations in an alliance with an arranged marriage between his 5-year-old niece Kaʻiulani and the 13-year-old Prince Yamashina Sadamaro. From extant letters to the king, both by Prince Sadamaro, upon the advice of his father, and by Japanese foreign minister Inoue Kaoru declined the proposal on behalf of the government of Japan. In February 1893, the Japanese Imperial Navy gunboat "Naniwa" was docked at Pearl Harbor with the Japanese prince on board. Rumors circulated in the American press that the Japanese considered intervening militarily.