Prime Minister Yoshiro Mori urged world leaders Thursday to adopt a step-by-step approach to reform the U.N. Security Council but stopped short of stating Japan's bid for a permanent membership on the council.

In a speech to the U.N. Millennium Summit, Mori underlined Japan's increased international role in the field of "human security," financial contributions and nuclear disarmament.

As an initial step to overhaul the Security Council, Mori called for an agreement initially to expand the number of both permanent and nonpermanent seats and assign the permanent membership to countries from both the developed and the developing world.

"I am convinced that a large majority of member states already support the expansion of the permanent and nonpermanent membership of the council, as well as the inclusion of both developing and developed countries in the expanded permanent membership," Mori said in a speech from the U.N. General Assembly podium.