Secretary of State Hillary Clinton urged Asia Friday to enforce tough sanctions against North Korea, which hit back by threatening a "physical response" to Washington's plans for joint military drills with South Korea.
Clinton, speaking in Hanoi at the Asia-Pacific's biggest security dialogue, also called on Myanmar's neighbors to pressure the country's military rulers for democratic reforms and said Asia must join the global community in sending a "clear signal" to Iran to curb its nuclear ambitions.
"One measure of the strength of a community of nations is how it responds to threats to its members, neighbors and region," Clinton told the 27-member ASEAN Regional Forum, which includes regional powers China, Japan and Russia along with the United States, European Union and Canada.
Clinton unveiled new U.S. sanctions this week against North Korea, blamed by both Washington and Seoul for the March sinking of a South Korean warship that killed 46 sailors and sharpened tensions over Pyongyang's nuclear program.
A North Korean diplomat said Washington's new sanctions and the U.S.-South Korean drills would be met with a "physical response," and that charges it torpedoed the South's warship had pushed the divided Korean peninsula "to the brink of explosion."
"There will be a physical response to the steps imposed by the United States militarily," Ri Tong-il, a member of Pyongyang's delegation in Hanoi, told reporters. The military exercises, he added, would violate North Korean sovereignty.
The new sanctions target the ruling elite in the impoverished and isolated communist state and build on earlier U.N. sanctions that curbed trade with the North in hopes of persuading it to abandon its atomic ambitions.
Clinton said it was essential Asian nations enforce the punitive measures to encourage North Korea "to take the steps it must" to stop nuclear development and seek real peace.
She later told reporters Washington hoped for the day when Pyongyang was "less concerned about making threats and more concerned about making opportunities."
Japan waded into the crisis, announcing plans to send four Maritime Self Defense Forces officers to the U.S.-South Korea exercises off the west coast of the divided Korean peninsula as observers, responding to invitations from the two countries.
This will be the first time Japan's self defense forces join a joint exercise by the United States and South Korea starting this weekend, a Defense Ministry spokeswoman said. The four officers will be aboard U.S. aircraft carrier George Washington.
No direct rebuke
Clinton had hoped to rally regional support behind Seoul, but fell short of building consensus for a direct rebuke of Pyongyang.
A senior U.S. administration official said the vast majority of countries at the Hanoi talks expressed regret over the sunken ship, but less than half were willing to condemn Pyongyang and potentially anger its powerful ally China.
In Hanoi, North Korea's foreign minister repeatedly denied any involvement in the sinking, according to diplomats present at the closed-door talks.
Clinton told reporters North Korea's belligerence prevented Washington from returning to six-party talks aimed at ending the North's nuclear weapons program in return for generous aid.
The naval exercises are the first overt military response to the attack on the warship.
The United States has said they are a show of force meant to convince the North to curb its "aggressive behavior" and will take place in international waters.
China has condemned the drills and launched its own exercises off its eastern coast.
Myanmar nuke program?
Clinton also urged Asia-Pacific ministers to put more pressure on Myanmar — a member of the Association of South East Asian Nations (ASEAN) which anchors the forum — to enact real democratic reforms and allow elections later this year which will be both free and credible.
President Barack Obama's administration has expressed frustration that, despite U.S. offers of greater engagement, Myanmar's military rulers have refused to budge on key demands.
These include the release of an estimated 2,000 political prisoners, such as Nobel Peace laureate Aung San Suu Kyi.
It has also said it is concerned by reports that Myanmar, formerly known as Burma, is seeking North Korean help to develop its own nuclear program, which, if true, could open an alarming new front in the battle against global proliferation.
Clinton's visit to Hanoi is part of the Obama administration's broader effort to boost U.S. engagement with Asia, in part to counter the rising influence of China.
Clinton also urged regional leaders to resolve longstanding territorial disputes over the South China Sea, which pit China against Vietnam and other regional countries in squabbles over the vast, potentially-oil rich maritime region.