"We have signed a contract with North Korea to buy this shipment in 1999 and we have no intention to purchase any other shipment," a senior government official told Reuters.

Washington released the unflagged So San on Wednesday, two days after it was intercepted in the Arabian Sea by Spanish warships acting on a U.S. tip-off.

Madrid said on Thursday Washington had apologised for "what could seem an absurd situation".

Spain has said 15 Scud missiles and conventional warheads as well as 85 drums of unidentified chemicals were hidden under cement bags on the ship.

But Washington decided the missile delivery was not breaking the law and freed the ship after Yemen gave assurances it would not hand them over to anyone else.

The release of the ship appeared to defuse a potentially explosive situation in a region where tensions have been high since the United States made clear it was prepared to go to war with Iraq over its suspected weapons of mass destruction.

But Richard Murphy, former U.S. ambassador to Saudi Arabia, told Italy's La Stampa on Thursday the freighter incident was "really very embarrassing to the United States".

"The fact that an ally of ours, right in the middle of the Iraqi crisis, buys 15 Scud missiles from North Korea shows that this alliance is very different from those we had during the Cold War, which were much more reliable," Murphy said.

The fiasco over the missile shipment was ridiculed in Europe's press which questioned Washington's tactics in its "war on terror".

Spain's conservative El Mundo demanded an explanation and queried whether Spanish ships should continue to support U.S. operations.
 

"MISSILES BOUGHT FOR DEFENCE"

Yemen said on Thursday the missiles were bought for defence purposes.

"Yemen like every other country in the region is concerned about its security, about the stability of the region. Our objective is basically defensive," Yemeni Foreign Minister Abubakr al-Qirbi told BBC radio.

"Yemen made the deal based on cost effectiveness."

Asked if the seizure of the ship was understandable given that the weapons were hidden, Qirbi said: "I think it was an understandable act. The (cargo) manifesto was not clear also. Once we discussed the matter with the Americans and they realised the correctness of the deal they released the ship.

"I think the Spanish really have intervened incorrectly and I'm sure that once they realise the facts they will be apologetic about it."

Yemen, ancestral home of al Qaeda leader Osama bin Laden, has joined Washington's war on terror but has yet to shake off its image as a haven for Muslim militants.

It has arrested dozens of al Qaeda suspects in a major crackdown as part of the U.S.-led war against terror.
 

"US APOLOGY"

A Spanish Defence Ministry spokesman said Madrid was "a little surprised" by Washington's decision to release the ship as it had declared North Korea part of an "axis of evil" along with Iraq and Iran.

He said the Pentagon's number two, Paul Wolfowitz, had called Defence Minister Federico Trillo on Wednesday "to thank and praise Spain for the operation and to apologise for what could seem an absurd situation".

But Spanish Foreign Minister Ana Palacio, a staunch U.S. supporter, told state radio she backed Washington's decision.

"Once all the details were checked and the origin, destination and buyers were verified, and Yemen guaranteed that these missiles were not going to pass into terrorist hands, we were obliged to let the ship follow its course," she said.

But El Mundo newspaper suggested Spain should withdraw its ships if Washington could not explain why it risked Spanish sailors' lives.

"In such a sensitive area, you can't have the feeling of ridicule felt by policemen when they arrest a criminal and see the judge let him out by the back door," it wrote.

Most of the European press was equally critical. "It looks like the Americans screwed up," France's Liberation remarked, while Britain's Guardian headlined its editorial: "Silly stunts are not serious policy".

But some commentators saw the seizure as Washington's way of proving North Korea was exporting missiles.

"The goal of this episode...was obviously to expose North Korea as an arms supplier," wrote the Austrian daily Die Presse. "The U.S. wanted to catch the North Koreans in the act."