Asia erupted in outrage Wednesday over a series of brazen North Korean missile tests, with wary nations denouncing the launches as provocative, threatening sanctions and vowing to take the matter to the U.N. Security Council.

Japan's military went on high alert and Australia warned of regional instability, while the White House said the audacious military exercise, which included the launching of a long-range Taepodong-2 believed capable of reaching the United States, would only worsen the impoverished communist nation's international isolation.

The U.N. Security Council was meanwhile planning to hold an emergency session Wednesday morning to discuss the situation, according to French Ambassador to the U.N. Jean-Marc de La Sabliere. The meeting was requested by the Japanese mission.

The Japanese were expected to present a resolution condemning North Korea's firing of its missiles, according to a U.N. diplomat speaking on condition of anonymity, as plans for the resolution have not been finalized.

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The missiles apparently fell harmlessly into the Sea of Japan, and U.S. officials said the long-range one failed shortly after take-off. But the tests come at an especially sensitive time, when nuclear-armed North Korea is stalemated with regional powers over negotiations that would have Pyongyang give up its nuclear program in exchange for badly needed aid.

It was also a reminder of 1998 when North Korea shocked the region by firing a Taepodong missile over Japan and into the Pacific Ocean. Following protests over that test, Pyongyang observed a moratorium on long-range missile launches since 1999.

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In Seoul, Suh Choo-suk, senior secretary to the South Korean president on national security, called the launch a "provocative act" and urged North Korea to return to the six-nation talks over its atomic weapons program.

The talks, held between North Korea, South Korea, China, the United States, Russia and Japan, have been stalled since last year over Pyongyang's insistence that Washington drop financial sanctions against it.

The sentiment was echoed by Australian Prime Minister John Howard, who condemned the launches, saying "North Korea is in total breach of international obligations in doing this and I hope that North Korea feels isolated and feels the condemnation not only of Australia, the United States and Japan but also of China and naturally of South Korea."

U.S. Secretary of State Condoleezza Rice planned to start conferring immediately with her counterparts from China, Japan, South Korea and Russia, and discuss U.N. Security Council action, National Security Adviser Stephen Hadley said.

The test launches came as the United States celebrated its Independence Day holiday and launched the space shuttle Discovery from Cape Canaveral, Florida.

In Tokyo, Japanese Foreign Minister Taro Aso called for the U.N. Security Council to be convened over the issue, while warning there is "very high possibility" it would level economic sanctions against North Korea.

Even Thailand, far out of range of North Korea's short-range missiles, protested, with Foreign Ministry spokesman Kitti Wasinondh saying Bangkok is "extremely concerned" and urging North Korea to return to the six-nation nuclear talks.