Japan is expected to take on a tougher stance in its long-festering territorial rows with South Korea and China as a hawkish leader of its main opposition party is seen likely to take its premiership in elections expected within months.

Former Prime Minister Shinzo Abe on Wednesday returned to the helm of the Liberal Democratic Party, pledging to make Japan a "strong nation" ― remarks highlighting his conservative, nationalist policy orientation.

Abe has said that he would visit the Yasukuni Shrine honoring war criminals, seek to recognize Japan's right of collective defense and reverse a series of Tokyo's apologetic statements over its wartime atrocities.

These, should they be put in action, may seriously damage ties with South Korea and China, where resentment over Japan's past militarism runs deep, with its territorial claims fanning nationalism ahead of leadership changes in both nations, experts warned.