North Korea reportedly starts fuelling rocket

SEOUL (Reuters) - North Korea has begun fuelling a long-range rocket it plans to launch between April 4-8, CNN said, starting a process that experts say means the rocket will be ready for lift-off in three to four days.

South Korea, Japan and the United States see the planned launch as a test of North Korea's longest-range missile, the Taepodong-2, and have said it would violate U.N. Security Council resolutions imposed after an earlier exercise in 2006.

Any attempt to punish North Korea will infuriate Pyongyang, which has threatened to restart its plant that makes arms grade plutonium and also quit nuclear disarmament talks if the United Nations takes action.

The U.S. news broadcaster quoted a senior U.S. military official as saying North Korea had begun fuelling the long-range rocket and it could be ready for launch by the weekend, according to a report on its website seen in Seoul on Thursday.

North Korea has said it is putting a satellite into orbit as part of its peaceful space programme.

The launch will be the first big challenge for U.S. President Barack Obama in dealing with the prickly North, whose efforts to build a nuclear arsenal have long plagued ties with Washington.

In London on Wednesday, a U.S. official, speaking on condition of anonymity on the sidelines of a G20 meeting, said Washington would respond to any North Korean launch by raising the matter in the U.N. Security Council.

"The president made clear we are deeply concerned about the prospective missile launch by the North Koreans ... There will be a reaction to it," the official said.

The United States, Japan and South Korea say they see no difference between a satellite and a missile launch because they use the same long-range rocket, the Taepodong-2, which is designed to carry a warhead as far as Alaska but exploded shortly into its only test flight in July 2006.

North Korea was hit with U.N. sanctions barring it from ballistic missile tests and halting its trade in weapons of mass destruction after it tried unsuccessfully to test the Taepodong-2 and conducted a nuclear test a few months later.

Several missile-interceptor ships with sophisticated radar from Japan, the United States and South Korea are expected to be in waters along the rocket's flight path but there are no plans to intercept it unless it threatens their territories.

For North Korean leader Kim Jong-il, a launch that he can portray as at least partially successful would be an important boost to his standing at home, and with the powerful military. He is thought to have suffered a stroke last August, raising speculation about the 67-year-old's grip on power.

(Additional reporting by Caren Bohan in London, Editing by Dean Yates)