Japanese Prime Minister Shinzo Abe told US President Donald Trump that the strengthening of their two nations’ alliance would be maintained even after Abe’s departure from office, a Japanese government spokesman said on Monday. Abe announced on Friday he was resigning because of poor health, his long-running battle with ulcerative colitis ending his tenure as Japan’s longest-serving prime minister. “He wants President Trump to rest assured because the policy of bolstering the Japan-US alliance will remain unchanged,” Deputy Chief Cabinet Secretary Akihiro Nishimura said. Nishimura was speaking to reporters after a 30-minute telephone call between Abe and Trump, early on Monday in Japan. Trump called Abe the “greatest prime minister in Japan’s history”, according to a White House spokesman.Abe told Trump that Japan would like to cooperate closely with the United States as it draws up a new missile defence strategy, Nishimura said. Japan in July took a step towards acquiring weapons that can strike North Korea, after a ruling party committee approved proposals to consider acquiring strike capability to halt ballistic missile attacks.