Tuesday marked the fifth anniversary of Prime Minister Shinzo Abe's sweeping return to power, making him one of the longest-serving leaders in a nation that had been notorious for a revolving door of prime ministers.

Abe, who made a comeback to the nation's top job in December 2012, is widely expected to seek a historic third term as president of the ruling Liberal Democratic Party in a leadership election slated for September next year. His victory in the LDP election, if achieved, would in turn put him on course to become Japan's longest-serving prime minister, extending his term until September 2021.

"I have faced numerous challenges in my five-year term in office, but the strong public support represented by a fifth consecutive election win — three in the Lower House and two in the Upper House — has allowed me to surmount those difficulties," Abe told reporters in his office on Tuesday morning.