SEOUL, South Korea — As North Korea fueled a multistage rocket Thursday for its threatened satellite launch, President Barack Obama promised a "stern" response and Japan vowed to press for an emergency session of the U.N. Security Council.
Senior U.S. defense officials said that trailers and vehicles carrying rocket propellant were in place at North Korea's coastal launch site and that fueling had begun.
A U.S. counter-proliferation official said the fueling process could take "up to a few days." But a senior U.S. intelligence official said that Pyongyang was on track for a projected Saturday launch.
The American officials spoke on condition of anonymity to discuss intelligence issues.
'Stern, united response'
At the G-20 summit in London, Obama and South Korean President Lee Myung-bak issued a statement agreeing on "a stern, united response from the international community if North Korea launches a long-range rocket."
State Department spokesman Robert Wood would not address the U.S. intelligence reports. But he repeated earlier warnings for the North Koreans not to take any "provocative" actions.
Japan's ambassador to the U.N. said his nation will request an emergency session of the Security Council if North Korea proceeds with the launch. Yukio Takasu said he raised the possibility during closed-door council talks Thursday.
Takasu and other council diplomats say they anticipate a possible emergency session as early as this weekend.
China urges calm in Japan
Chinese President Hu Jintao urged Japan to handle the expected firing of a rocket by North Korea over Japanese territory calmly, though he says Beijing is working to avert the launch. Hu made the comment in a meeting late Thursday with Japan's prime minister, Taro Aso, on the sidelines of the G20 meeting, said Osamu Sakashita, Aso's deputy cabinet secretary for public relations.
China says it is trying in various ways to dissuade Pyongyang from conducting the communications satellite launch that is widely believed to be a test for a long-range missile.
North Korea heightened its militarist rhetoric toward the U.S., Japan and South Korea on Thursday, threatening retaliation for any attempt to shoot down the rocket. Quoting an unidentified North Korean general, the North Korean Central News Agency said Japan would be struck with a "thunderbolt of fire" if it attempts to intercept the multistage rocket.
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The North Korean news service also issued a veiled threat against American warships moving in position to monitor the launch, saying: "The United States should immediately withdraw armed forces deployed if it does not want to receive damage."
Video: ‘Stern response’ Some U.S. lawmakers are urging Obama to shoot down the rocket if it endangers the United States or its allies. Defense Secretary Robert Gates said during a weekend TV interview that the U.S. had no plans to intercept the rocket — though it might consider the move if an "aberrant missile" were headed to Hawaii "or something like that."
U.S. officials have been keeping tabs on North Korea's launch preparations with satellite imagery and other surveillance. North Korea has complained that the U.S. is also using high-altitude U-2 spy planes and has warned the aircraft would be shot down.
North Korea's pre-launch movements are similar to the steps taken in advance of its 2006 firing of a Taepodong-2 missile, the U.S. intelligence official said.
The fueling starts an informal pre-launch phase that precedes the formal countdown.
"You need to launch within a few days because rocket fuel is typically quite corrosive," said Jeffrey Lewis, an arms control expert at the New America Foundation in Washington, D.C.
Video: Marketing ploy? U.S. intelligence analysts continue to believe that North Korea aims to launch a communications satellite rather than conducting a missile test, which would violate a U.N. resolution. However, the rocket launch would yield data directly applicable to its long-range ballistic missile program.
The issue was top of the agenda Thursday when Obama met with his South Korean counterpart, Lee Myung-bak, on the sidelines of the G-20 summit in London. Obama pledged to push for "peace and stability," while Lee's office issued a statement saying the two leaders agreed to keep working on a verifiable dismantling of North Korea's worrisome nuclear programs.
Russia appeared to be edging closer to Washington's position in an apparent show of goodwill. But a strong united response likely would prove difficult given that China — the North's closest ally — has veto power in the Security Council. Beijing continued to urge all sides to show restraint.
North Korea is warning against any effort to intercept the rocket, take the issue to the Security Council or even monitor the launch. It says its armed forces are at a high level of combat-readiness.
Debris from the rocket could fall off Japan's northern coast, North Korea has said. Tokyo has deployed warships and missile interceptors there as a precaution, but says it has no intention of trying to shoot the missile down on its own.
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