SINGAPORE — North Korea, which launched a long-range missile over Japan in April, appeared Saturday to be moving another one to a launch pad.
Meanwhile, the United States and its Asian allies are laying the groundwork for a tougher stance should negotiations with China and Russia fail to yield a new strategy to force the North Korean government to give up its nuclear program, defense officials said Saturday.
Reports that a large rocket was moving by train toward North Korea's east coast punctuated a tense week on the Korean peninsula. It began Monday with the North's underground test of a nuclear device, included six short-range missiles fired into the Sea of Japan, and featured a declaration by the government of Kim Jong Il that the truce that ended the Korean War was null and void.
In Singapore at a regional defense meeting, Secretary of Defense Robert Gates signaled Saturday that the United States and many of North Korea's neighbors are getting fed up. He told his South Korean and Japanese counterparts that they should begin thinking about measures the three countries could take unilaterally if the so-called six-party talks continued to founder.
"We will not stand idly by as North Korea builds the capability to wreak destruction on any target in Asia — or on us," Gates said. He said that he did not call North Korea's nuclear program a direct threat to the United States but that it was a "harbinger of a dark future."
Gates told defense officials at the meeting that the U.S. government understands and disdains the game of brinkmanship North Korea is playing.
"They create a crisis, and the rest of us pay the price to return to the status quo ante," he said. "As the expression goes in the U.S., I'm tired of buying the same horse twice."
U.S. defense officials stressed, however, that they still hoped to revive the six-party talks.
The missile recently spotted on a cargo train resembled the Taepodong II missile that North Korea launched over northern Japan into the Pacific Ocean on April 5, an unnamed official told Yonhap, the South Korean news agency.
Yonhap quoted other South Korean officials who said activity had been spotted around a factory in the North known to build long-range missiles.
The long-range launch in April, which violated U.N. resolutions and triggered condemnation from the U.N. Security Council, demonstrated to American experts that North Korea has made significant progress in multistage rocket technology.
Once North Korea perfects a three-stage intercontinental ballistic missile the size of the Taepodong II, experts say, it may have enough range to strike the western United States.
This spring, North Korea's marriage of missile and nuclear tests fits into what U.S. intelligence agencies and independent experts agree is an attempt to fashion a nuclear warhead small enough to fit atop the North's growing arsenal of missiles.
In both missiles and nuclear bombs, experts say, North Korea appears to be making progress but still has a long way to go before it will have reliable bombs that can be consistently delivered by long-range missiles.
In Singapore on Saturday, defense ministers from South Korea and China joined Gates in expressing annoyance at the North's recent behavior.
"North Korea, perhaps to this point, may have mistakenly believed that it could be perhaps rewarded for its wrong behaviors," South Korean Defense Minister Lee Sang Hee said. "But that is no longer the case."
Lt. Gen. Ma Xiaotian, the second in command of the Chinese military's General Staff, said China "has expressed a firm opposition and grave concern about the nuclear test."