SEOUL, South Korea — Defying warnings of tougher sanctions from Washington, North Korea launched a rocket Sunday that Western experts believe is part of a program to develop intercontinental ballistic missile technologies.
The rocket blasted off from Tongchang-ri, the North's main satellite launch site near its northwestern border with China, a spokesman for the South Korean Defense Ministry said.
The three-stage rocket dropped its first stage about two minutes after takeoff and disappeared from radar four minutes later, as soon as it dropped its fairing, a nose cone used to protect its payload, Moon Sang-gyun, a spokesman for the South Korean Defense Ministry, said. When it disappeared from radar, the rocket was 240 miles above waters southwest of South Korea and 490 miles south of the launch site, he said.
"We are working together with our American ally to assess the launch and tell whether it was a success," he said.
President Park Geun-hye of South Korea called an emergency meeting of top national security advisers Sunday to address the launch, her office said. South Korea, the United States and Japan requested an emergency meeting of the U.N. Security Council.
In Washington, Secretary of State John Kerry called the launch a "major provocation, threatening not only the security of the Korean Peninsula, but that of the region and the United States as well." Susan E. Rice, the national security adviser, said it was "a flagrant violation" of Security Council resolutions.
North Korea had earlier notified the International Maritime Organization, the U.N. agency responsible for navigation safety, that it planned to launch a rocket between Monday and Feb. 25 to put a satellite into orbit.
The United States and its allies condemned North Korea's plan because they consider its satellite program to be a sort of cover for developing an intercontinental ballistic missile capable of delivering a nuclear bomb. Under a series of Security Council resolutions, North Korea is prohibited from developing nuclear weapons or ballistic-missile technologies.
The North's latest move was sure to add impetus to the U.S. call for tougher sanctions.