Japan's recent moves to lift constitutional restrictions on its armed forces are a flagrant violation of the Potsdam Declaration, a major international agreement for establishing the post-World War II international order, sources from a briefing by the State Council Information Office said on Thursday.

"Japan's behavior has greatly undermined the political base for the Sino-Japanese relationship and hurt the feelings of Chinese people, as China was the most affected by Japan's invasions during World War II," Zhao Jianwen, a researcher at the Institute of International Law of the Chinese Academy of Social Sciences, said at the briefing.

Japan's ruling coalition pushed its contentious package of security bills through the lower house of the Diet, the national legislature, earlier in the day despite a boycott of the vote by most opposition members.