WASHINGTON/SEOUL - North Korea's missile preparations suggest Pyongyang could launch a satellite into space as early as Saturday, an American defense official said on Thursday as the U.S. military monitored the situation.

At the United Nations, Japan's U.N. ambassador, Yukio Takasu, said his country would request an emergency meeting of the Security Council to discuss a possible response if North Korea launched the long-range missile in the coming days.

The United States and others have threatened North Korea with punishment if they launch the long-range missile.

They're doing everything consistent with the launch of a space vehicle on April 4, the U.S. defense official told Reuters on condition of anonymity.

Pyongyang has said it will send a satellite into orbit between April 4-8 but the United States, South Korea and Japan say the launch is a disguised test of the long-range Taepodong-2 missile, which is designed to carry a warhead to U.S. territory.

Earlier, CNN reported that North Korea had begun fueling a long-range rocket and could launch it by the weekend.

Takasu told reporters intensive diplomatic efforts were under way to persuade Pyongyang not to launch the rocket, which he said would represent a threat to the security of Japan and further increase regional and international tensions.

He said an emergency Security Council session on North Korea could take place this weekend if the missile is fired.

A U.S. official said after a meeting between President Barack Obama and South Korean President Lee Myung-bak on the sidelines of the G20 summit in London that it looked like North Korea would proceed with the launch but Washington was trying to persuade Pyongyang to stop.

The two leaders agreed the launch would violate Security Council resolutions, the unidentified U.S. official said.

We have been making maximum efforts to try to dissuade them and still hope that they may change their minds, the official said.

Japan has sent missile-intercepting ships along the rocket's flight path, which takes it over the Asian economic power, and said it could shoot down any debris such as falling booster stages that threatens to strike its territory.

North Korea, which has issued numerous threats concerning the launch, used some of its strongest language in its latest rhetorical blast.

If Japan recklessly 'intercepts' the DPRK's (North Korea's) satellite for peaceful purposes, the Korean People's Army will mercilessly deal deadly blows not only at the already deployed intercepting means but at major targets, a military spokesman was quoted as saying by the North's KCNA news agency.

North Korea has deployed the newest jet fighters in its aging air force to an air field near the Musudan-ri launch site to prepare for any contingencies, South Korea's biggest daily Chosun Ilbo quoted government sources as saying.

South Korea's transport ministry ordered its domestic carriers to stay out of the rocket's flight zone from April 4-8, which will affect about 20 flights a day.

CHALLENGE TO OBAMA

A launch would be the first big challenge for Obama in dealing with the prickly North, whose efforts to build a nuclear arsenal have long plagued ties with Washington.

The United States, Japan and South Korea say they see no difference between a satellite and a missile launch because they use the same rocket, the Taepodong-2, which exploded shortly into its only test flight in July 2006.

U.N. Security Council resolutions reached after the Taepodong-2 test in July 2006 and North Korea's only nuclear test a few months later bar the state from ballistic missile testing and halt most of its weapons trading.

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

Japan's Kyodo news agency quoted U.N. diplomatic sources as saying Japan and the United States would shelve their proposal to seek the adoption of a Security Council resolution calling for additional sanctions in the event of the missile launch.

The two countries intend instead to propose a resolution seeking reinforcement of the effectiveness of existing sanctions against Pyongyang, the sources said.

Analysts had said they expected China, a veto-wielding member of the Security Council and the closest thing Pyongyang can claim as a major ally, to block any new sanctions or attempts to tighten the enforcement of existing ones.

The launch is a risk for the cash-strapped North. A failure would hurt missile sales, one of its few export businesses, and embarrass North Korean leader Kim Jong-il, 67, whose suspected stroke in August raised questions about his grip on power.

A successful launch, just ahead of the annual meeting of North's parliament next week, would put to rest any questions about Kim's power, analysts said.

Japan Barack obama South Korea Launch