KYOTO -- Nearly two dozen former political leaders and policy experts from around the world met in Kyoto on Tuesday for informal discussions on how to make the United Nations more effective in responding to international security threats.

The first day of the two-day meeting focused on the challenges to international security, including terrorism and the proliferation of weapons of mass destruction.

"It is vitally important to discuss how the U.N. and the Security Council should be reformed, and what part they should play to undertake more effective collective action," Foreign Minister Yoriko Kawaguchi said in her opening remarks.

Although not an official U.N. conference, the deliberations in Kyoto will be passed on to a U.N.-sanctioned group of former government experts looking at ways to reform the U.N., which will meet in Vienna next month.

There remain fundamental differences among developed and developing nations as to what constitutes a greater threat to security.

Developed nations often see stopping terrorist attacks as the top priority.

Developing nations argue, however, that international security is best secured by first tackling health and poverty issues, which they maintain are the root causes of terrorism.

Sadoko Ogata, director of the Japan International Cooperation Agency and one of the Kyoto participants, said Tuesday's meeting reaffirmed a broad agreement that collective action is needed to solve security issues, but conceded that developing nations have different concerns on how best to seek a solution.