U.S. Says North Korean Missile Test Failed

— -- The U.S. military has assessed that North Korea failed in its attempt to launch what was presumably an intermediate-range mobile-launched Musudan missile. An explosion was detected shortly after the missile was launched early Friday morning, Korea time, from a location in eastern North Korea.

Before the launch, U.S. officials speculated it was possible North Korea might test launch the missile as early as Friday to mark the birthday of Kim Il Sung, Kim Jong Un’s grandfather and the first leader of North Korea.

"U.S. Strategic Command (USSTRATCOM) systems detected and tracked what we assess was a failed North Korean missile launch at 3:33 p.m. CDT (4:33pm EDT)," said Lieutenant Colonel Martin O"Donnell, a USSTRATCOM spokesman. "According to North American Aerospace Defense Command, the missile launched from North Korea did not pose a threat to North America."

A U.S. official told ABC News that "there was an explosion" shortly after the missile launched, which was presumed to have been a Musudan. The official said it was unclear if the explosion occurred in mid-flight or was the result of the missile crashing into the ground.

American officials had said for a week that the U.S. had detected activity in eastern North Korea related to North Korea's mobile launch systems. However, they urged caution as to whether that was a firm indication of a pending missile launch since it’s always unclear what North Korean intentions might be.

Officials cited the Musudan missile as the most likely missile system to be launched, though the longer range KN-08 and the newly developed KN-14 were also discussed as possibilities. The intermediate range Mususdan is believed to have the capability of reaching the American territory of Guam.

The other two longer range systems are believed to have the capability of reaching the continental U.S., though none of the three systems have been launch-tested.

The longer range KN-08 has drawn the most concern because it is believed that it might have the capability to reach the continental United States. However, the three mobile launched systems have drawn concern from the United States because their mobility makes them easier to conceal and they can be launched on short notice.

The launch of a mobile-launched missile is the latest provocation from North Korea this year. In January, North Korea conducted an underground nuclear test followed in February by a rocket launch that placed a satellite in orbit.

“The intel community assesses the probability of North Korea fielding a successful road-mobile ICBM with a miniaturize nuclear device that can range the homeland as low," Admiral William Gortney, the commander of U.S. Northern Command told a congressional panel Thursday. "As the commander accountable for defending the homeland, I choose to assess that he does have that capability and I think it’s the prudent course of action.”

“We need to see that end-to-end test but I’m not waiting for that end-to-end test on my assessment,” he added.

Mobile long range systems are of particular concern if North Korea succeeds in miniaturizing a nuclear weapons, a claim they made last month.

Korea’s Yonhap News Agency reported Wednesday that South Korea's Defense Ministry said North Korea has deployed one or two Musudan intermediate-range ballistic missiles near the eastern port city of Wonsan for a possible launch pegged to Kim Il Sung’s birthday.

In April 2013, U.S. intelligence detected North Korean troops setting up Musudan erector platforms at various locations on multiple occasions, but no launches took place.