The State Department slapped the punishment on the Stalinist state's Changgwang Sinyong Corporation, but stuck to its decision last year not to punish Yemen for ordering the consignment.

"We have assurances that this was the last part of the shipment and that there will be no further shipments," said State Department spokesman Richard Boucher.

"In consideration of our relationship, our cooperation on terrorism and consistent with the law, we're not imposing sanctions on Yemen for this activity at this time."

Crews of two Spanish navy vessels acting on US intelligence data, discovered the missiles after stopping and searching an unflagged merchant ship off the Yemeni coast last year.

But embarrassed US officials concluded that they had no power under international law to confiscate the missiles, which the Yemeni government said were intended for purely defensive purposes.

North Korea's missile development program has sparked concern for years, especially in Japan and the United States.

Washington is worried that the Stalinist state could deploy ballistic missiles capable of hitting US territory, and the prospect of them being twinned with nuclear weapons has sparked deep alarm.

The United States and North Korea have been locked in a standoff since October on Pyongyang's nuclear weapons program, after a senior US official accused Pyongyang of breaching a 1994 anti-nuclear pact.

Changgwang Sinyong Corporation has been found in violation of US arms export control laws on at least five previous occasions, including earlier this month.

The sanctions last three years and eight months and apply to all activities of North Korea relating to development and production of missile technology, electronics electronics, space systems or equipment, and military aircraft.

They include the denial of all US government licenses for the sale of such equipment, a denial of US contracts for the equipment and a ban on its importation into the United States, the State Department said in a notice published in the Federal Register.

The sanctions are entirely symbolic as the United States already prohibits almost all trade with North Korea.

Changgwang Sinyong was last hit with US sanctions on July 3 for arms sales to Iran that the State Department said could "make a material contribution to weapons of mass destruction or missiles."

In addition, it was punished for the same offense in 2001 and in 2000, 1998 and 1996 for violating missile-specific US export regulations.

In March of this year, the company was penalized by the United States in March for an alleged barter deal in which Washington claimed Pyongyang swapped missile components for expertise in developing a nuclear program from Pakistan.

SPACE.WIRE