Defense chiefs from Japan and the United States agreed Wednesday that Tokyo, Washington and Seoul should continue to closely cooperate in developments on the Korean Peninsula.

During a meeting in Tokyo, Defense Agency Director General Hosei Norota promised U.S. Defense Secretary William Cohen that he will do his utmost to have bills related to the new Japanese-U.S. defense cooperation guidelines approved during the upcoming regular Diet session, agency officials said.

Both Norota and Cohen shared concerns on North Korea's firing over Japan of what both say was a missile, and on an underground site suspected of being a nuclear facility, the officials said.