Kono has said the international community should maintain sanctions and pressure on North Korea until it takes concrete actions for denuclearization.

The North has sharpened its rhetoric against Tokyo amid reports that it seeks to put stern words against the North's nuclear program into statements to be adopted by the leaders of South Korea, Japan and China during a three-way summit in Tokyo on Wednesday.

On Sunday, the Rodong Sinmun, the ruling Workers' Party newspaper, also slammed Japan for "trying to free ride" on recent diplomatic progress.

"What it has to remember is that it can never evade the fate of the left-out person if it behaves disgusting while repeating the old cliche of 'sanctions' and 'pressure' as now," the newspaper said in a commentary.

North Korea and Japan have recently shown signs of reconciliation. The North's leader Kim Jong-un expressed his willingness to hold talks with Japanese Prime Minister Shinzo Abe during his summit with South Korean President Moon Jae-in on April 27, Moon's aides have said.

Abe has also said Tokyo is willing to talk with Pyongyang to possibly normalize ties and resolve the issue of Japanese nationals abducted by the North. (Yonhap)