Singapore : The United States said on Saturday it is weighing new options beyond the United Nations to punish North Korea, which the South blames for the sinking of a warship that has escalated tensions on the peninsula.
Seoul has complained to the U.N. Security Council over the sinking of the corvette Cheonan in March, killing 46 sailors. It blames the shadowy North for torpedoing the ship, although it is unclear what it wants from the United Nations.
US Defense Secretary Robert Gates told a security conference in Singapore it was the "collective responsibility" of Asian states to address North Korean "provocations," increasing pressure on a reluctant China to rebuke its long-time ally.
Gates and other US officials also suggested the United States was looking beyond measures in the U.N. Security Council and could act unilaterally or in concert with its allies to increase Pyongyang`s isolation.
The sinking of the Cheonan was deadliest single incident on the peninsula since the 1950-53 Korean War.
To try to deter the North, Gates said the United States would conduct more joint military exercises with South Korea and support "action" by the Security Council. He added without elaborating: "At the same time, we are assessing additional options to hold North Korea accountable."
US officials said Washington was looking at a range of options, including tightening economic sanctions to expanded searches of North Korean vessels.
Washington has also made clear it wants more help from China.
"The nations of this region share the task of addressing these dangerous provocations," Gates said. "Inaction would amount to an abdication of our collective responsibility to protect the peace and reinforce stability in Asia."
North Korea denies responsibility for the sinking and accuses South Korean President Lee Myung-bak of staging the incident to help his chances in local elections this week.
In increasingly shrill rhetoric, the North has warned several times through its official KCNA news agency that "war could break out at any moment."
Lee pledged to clamp down on any action deemed threatening but dismissed the likelihood of open conflict.
"There is no possibility of a war. There has been occasionally and locally peace-threatening behavior but we will strongly suppress it," Lee`s spokesman, contacted by telephone, quoted him as telling businessmen at the Singapore summit, known as the Shangri-La Dialogue.
US military officials, including Admiral Robert Willard, head of the US Pacific Command, have also played down such an outcome, saying there were no signs North Korea was preparing a nuclear test or moving troops toward the South.
However, they have also said the United States was prepared for a confrontation with the North. "American military power, and particularly conventional military power, is in my view as strong today as it has ever been in the Pacific. We are looking at ways to strengthen it further," Gates said.
Planned US-South Korea military drills, however, might be put off until it is clear what action the United Nations takes.
At the same time, relations between the United States and China have chaffed since the Obama administration told Congress in January of a plan to sell Taiwan, which Beijing regards as a renegade territory, up to $6.4 billion worth of arms.
China broke off military ties between the Pacific powers earlier this year as a result of the sales. Gates said on Saturday that decision could undercut regional stability.
Some US officials see the friction with China as particularly worrisome given the tension on the Korean peninsula.
As a permanent member of the Security Council, China can veto any proposed U.N. resolution or statement chastising the North.
China, Western diplomats say, will not tolerate new sanctions against North Korea, while Seoul appears determined to have the council at least agree on some form of rebuke of North Korea.
Beijing, which is North Korea`s only major ally and which fought alongside the North in the Korean War, has declined publicly to join international condemnation of Pyongyang, saying it is still assessing the evidence.
Major General Zhu Chenghu of the National Defense University challenged Gates at the Singapore summit, saying China was not to blame for stalling military-to-military ties and the arms sales to Taiwan sent the message America saw China as "enemies."
Gates rejected the characterization, saying China and the United States were partners in many areas.
But underscoring the gap in perceptions, Zhu also asked Gates why the United States made a distinction between the Cheonan`s sinking, which Washington swiftly condemned, and Israel`s deadly raid on an aid flotilla bound for the Gaza Strip this week.
"There`s no comparison whatsoever," Gates said. While Pyongyang carried out a "surprise" attack, Gates said the aid flotilla was warned in advance and had a chance to turn back.