Mr. Bush, Japanese Prime Minister Junichiro Koizumi, and South Korean President Kim Dae-Jung made the demand in a joint statement at an Asia-Pacific regional forum at the Mexican resort town of Cabo San Lucas.
Speaking earlier Saturday, Mr. Bush said his goal is to convince North Korean leader Kim Jong-il that it is in his interests -- and the world's --for him to disarm.
President Bush and China's President Jiang Zemin pledged during talks Friday at Mr. Bush's Texas ranch to oppose any nuclear weapons on the Korean peninsula.
The two-day summit in Mexico of leaders of the 21-nation Asia Pacific Economic Cooperation Forum -- APEC -- is opening Saturday to discuss trade, terrorism, Iraq, and North Korea. Mr. Bush is expected to make his case to the leaders for a tough new United Nations resolution on disarming Iraq and its suspected weapons of mass destruction.