Abe comfortably beat his only contender, former Defence Minister Shigeru Ishiba, by securing 553 out of a total 807 votes, reports The Japan Times.

He won 329 out of the 402 valid ballots cast by LDP MPs and 224 out of the remaining 405 votes allocated to party branches in each prefecture based on the number of members age 18 or older who have paid party fees.

His extended term in office signals the possibility that Abe, who has already been at the helm of the world's third-largest economy for nearly six years in his second stint as Prime Minister, may become the longest-serving premier in Japanese history.

With his renewed leadership, Abe is likely to reshuffle his Cabinet in the coming weeks, reportedly as soon as early October.

Abe has credited himself with "restoring a decent economy" under his Abenomics policy and taking the Japan-US alliance to a stronger level.

He also repeated that it's the "responsibility of the LDP" to revise the war-renouncing Article 9 of the Constitution to formalise the ambiguous status of the Self-Defense Forces - the nation's de facto military - which he said "protects the peace and independence of Japan".