The 65-year-old leader of the conservative Liberal Democratic Party (LDP) marked 2,887 days as head of the Japanese government on Wednesday, overtaking Taro Katsura, who served as Prime Minister three times between 1901 and 1913, Efe news reported.
Abe became Prime Minister in 2006 but resigned a year later over health issues, before returning to the post in December 2012.
Abe, who in principle could remain in power until his third and final term as LDP party leader ends in September 2021, said he feels "great responsibility" for the rest of his tenure.
The Prime Minister said the main challenges facing Japan are getting out of deflation, solving problems arising from low birth rates and accelerated demographic aging, and reforming the Japanese constitution, state broadcaster NHK reported.
Modifying the constitution, and in particular the pacifist article that limits defence capabilities, is one of Abe's great political priorities, but currently does not have enough support in the two chambers of the Diet (parliament) to achieve such reform.
Likewise, the economic strategy known as "Abenomics" has allowed Japan to continue on the path of growth, although it has been weak and is threatened by the persistent fragility of domestic consumption or by the decline in exports.
Currently, Abe does not see his leadership threatened owing to a fragmented opposition, and everything indicates that he will exhaust his mandate and set a new longevity record in power.
( With inputs from IANS )