Former House of Representatives speaker Yohei Kono says Prime Minister Shinzo Abe's recent statement to commemorate the 70th anniversary of the end of World War II is not convincing enough to help improve Japan's strained relations with China and South Korea.

"I have to say that (the statement) cannot be a trigger to improve relationships between Japan and China, and Japan and South Korea," he said in a speech Thursday in Osaka.

As chief Cabinet secretary in 1993 Kono delivered a landmark apology to "comfort women" who were forced to work in Japanese military brothels before and during the war. The women were mostly from the Korean Peninsula, and other parts of Asia.