Yohei Kono, a former Lower House speaker and the father of Foreign Minister Taro Kono, criticized Prime Minister Shinzo Abe on Wednesday for what he called the poor handling of North Korea's nuclear and missile threats, urging him to work more closely with China.

The United States, Japan and South Korea have been eager to cooperate in putting pressure on Pyongyang, but "have not tried to proceed with policies (against the North) with China," Kono, a former foreign minister, told the Japan National Press Club.

"It is obvious that China is the country that can persuade North Korea as China accounts for most of North Korea's trade. Even if the United States imposes tougher economic sanctions, their effectiveness would hinge on China's moves," Kono said.