North Korea and Burma are high on the agenda as Asia Pacific and western nations meet in Hanoi, Vietnam, for talks on regional security and cooperation.
The Association of Southeast Asian Nations' Regional Forum is meeting Friday for annual talks among representatives of 26 nations and the European Union.
Security issues, rights abuses by Burma and alleged aggression by North Korea are expected to be the key topics of discussion.
Burma, a member of ASEAN, is under fire for rampant human rights violations and plans this year to hold elections, the first in two decades.
Burma's detained democracy leader Aung San Suu Kyi is banned from the elections, which critics say are designed to keep the military in power.
North Korea is seeking diplomatic support at the forum over the sinking of a South Korean navy ship that killed 46 sailors.
Washington and Seoul say the North torpedoed the ship and plan joint military exercises this weekend as a show of force.
Pyongyang denies it was responsible and a North Korean spokesman at the forum warned Washington to call off the exercises if it wants a nuclear free Korean peninsula.
U.S. Secretary of State Hillary Clinton is attending the forum. She told ASEAN ministers Thursday America's future was intimately tied to the Asia Pacific.
"The United States is a Pacific Nation and we are committed to being an active partner with ASEAN and with all of you," she said. "Our partnership is rooted in common interests. We are committed to assisting the nations of Southeast Asia to remain strong and independent and that each nation enjoys peace, stability, prosperity, and access to universal human rights."
Clinton noted the region is the sixth largest market for U.S. exports and has more American business investments than China.
The United States, under President Obama, has become more active in Southeast Asia and has begun a policy of engaging Burma while maintaining economic sanctions.
Clinton on Wednesday announced new sanctions against Pyongyang and U.S. lawmakers Thursday voted to renew sanctions against Burma for human rights violations.
But ASEAN, which includes several authoritarian governments, is against sanctions and is more reluctant to criticize member Burma and North Korea.
ASEAN ministers issued a statement this week urging free, fair and inclusive elections in Burma.
The ministers also deplored the sinking of the South Korean ship, which they called an "incident," and rising tensions on the Korean Peninsula.
But their statement stopped short of criticizing Burma and did not even mention North Korea, saying only that it supported efforts for a nuclear weapons free Korean peninsula.
ASEAN members are Brunei, Burma, Cambodia, Indonesia, Laos, Malaysia, the Philippines, Singapore, Thailand, and Vietnam.