Prime Minister Shinzo Abe says he shares with past Japanese governments the historical view that admits Japan inflicted enormous damage and pain on Asian countries.
Last month, Abe said in the Diet that there is no fixed definition for "aggression," either academically or in terms of international law.
He made the remark in reference to the 1995 statement by then prime minister Tomiichi Murayama, who expressed deep remorse for Japan's history of colonization and aggression in Asian countries.
Abe's remark was harshly criticized by South Korea.
At an Upper House committee meeting on Wednesday, Abe said he had simply wanted to note that there are various academic debates about the definition of "aggression."
He said that, as a politician, it's not appropriate for him to go into the details, and added that academics have yet to settle on an absolute definition of the term.
Abe also stressed that Japan has achieved development in the postwar era based on sincere reflection of its remorse over past actions while respecting freedom, democracy and basic human rights.