Dialogue, meanwhile, between Japan and Russia.
They held their third "two-plus-two" meeting on Tuesday... involving their ministers of foreign affairs and defense.
They focused on resolving the territorial dispute over the Kuril Islands, which Russia claimed at the end of World War 2.
On North Korea, both sides agreed that the regime needs to get rid of its nuclear weapons.
Kim Hyo-sun tells us more.
The foreign and defense ministers of Japan and Russia met in Moscow on Tuesday to discuss issues of common interest.

"Russia is an important neighbor, and we hope that by maintaining dialogue and cooperation, it will lead to the moment when hazardous situations and tensions don't arise."

Japan and Russia discussed using economic cooperation to resolve an ongoing dispute over four Pacific islands which Russia calls the Kuril Islands, and Japan calls the Northern Territories.

"The business venture by Japanese entrepreneurs, with the participation of Russian partners, will take place within the framework of the preparation of joint economic projects on the Southern Kuril Islands on August 16th-20th this year. Following the results of this business venture we will arrange the dates of the next round of consultations on joint economic projects within the framework of work on the peace treaty."

During the talks,... Tokyo also explained that the Japanese missile defense system including the Aegis Ashore is not a threat to Russia, but purely a defensive system.
Japan and Russia also touched upon the North Korean nuclear issue,... agreeing to cooperate closely to achieve their common goal of denuclearizing the Korean Peninsula.
The possibility of a summit meeting between President Vladimir Putin and Prime Minister Shinzo Abe in September on the sidelines of the Eastern Economic Forum in Vladivostok was also discussed,... and the two countries agreed on an annual ministerial-level "two-plus-two" meeting.
Kim Hyo-sun, Arirang News.