Dr Yasushi Watanabe, an expert in public diplomacy at Keio University, points to Mr Abe's wide recognition internationally; he is Japan's longest-serving prime minister, having held office since 2012.

"Prime Minister Abe has put a lot of his time and energy in diplomacy. I have never seen a Japanese prime minister who travels all around the world. This is coupled with recent special occasions such as G20, World Rugby Cup and the Imperial Ascension," he said.