Territorial disputes in the South China Sea are expected to top the agenda at a meeting of Southeast Asian defense ministers that started Wednesday in Brunei.
Senior defense officials from the United States, China, Japan, South Korea and other regional powers are also attending the two-day ASEAN summit.
Ahead of the meetings, some ASEAN foreign ministers agreed to present a unified front in encouraging China to negotiate a binding code of conduct to help prevent conflict in the territorial disputes.
Officials say U.S. Defense Secretary Chuck Hagel plans to encourage such talks as he meets with his Chinese counterpart, General Chang Wanquan, on the sidelines of the meeting.
China, which has overlapping territorial claims with several Southeast Asian countries, has been reluctant to deal with ASEAN on the disputes, instead preferring to handle them on a country-by-country basis.
Brunei, the Philippines, Taiwan, Vietnam and Malaysia are embroiled in territorial disputes with China over several resource-rich islands in the South China Sea. Japan and China are engaged in a separate dispute in the East China Sea.
Many of the nations accuse China of using its rapidly advancing military to more aggressively defend what it views as its territory. Some of the nations have expanded their defense cooperation with the United States, as a result.
The ASEAN Defense Ministerial Meeting Plus, as it is known, will help lay the groundwork for October's East Asian Summit, which will be attended by world leaders, including U.S. President Barack Obama.