Japans Prime Minister Yukio Hatoyama and South Korean President Lee Myung Bak agreed North Korea must return to nuclear disarmament talks, saying sanctions should remain until the communist country agrees to do so. The summit between the two came less than a week after North Korean leader Kim Jong Il told Chinese Premier Wen Jiabao that his country is prepared to return to six-party nuclear disarmament negotiations. South Korea and Japan have agreed to work together toward comprehensive and fundamental solutions for North Korea nuclear issues, Lee said today at a joint press conference in Seoul with the visiting Japanese premier. We agreed to make diplomatic efforts with opening dialogue channels for North Koreas return to six-nation talks.