The seizure and release of a North Korean missile shipment bound for Yemen may have further alienated the reclusive dictatorship in Pyongyang, hurting U.S. efforts to pressure the regime to end its nuclear weapons program, analysts say.

North Korea said Thursday it will reactivate a nuclear power plant that was frozen under a 1994 deal with the United States. U.S. officials suspect the plant was being used to develop weapons.

The announcement followed this week's incident in the Arabian Sea, which North Korea observers said might lead the nation to accelerate its nuclear weapons program. The United States had never before publicly tried to intercept a North Korean missile shipment.

"It undercuts our goals and it looks like the Keystone Kops," said Lee Feinstein, a former State Department official under President Clinton. "We're snatching defeat from the jaws of victory. It's difficult to track these missile shipments, then when we have a major success in tracking and boarding this ship, we have to let it go."

Or, North Korea could interpret the move as a signal that the United States has abandoned diplomatic overtures in favor of hardball tactics, said Daniel Pinkston, a Korea expert at the Monterey Institute for International Studies.

"It may empower the hard-liners and embolden them to say, 'Look, we told you we couldn't deal with the Americans, the only way to deal with this situation is to strengthen ourselves militarily, and we need nuclear weapons to deter the United States,'" Pinkston said.

North Korea stunned U.S. officials in October by defiantly admitting it was conducting a secret program to enrich uranium to make nuclear weapons. The program violated a 1994 pact in which Pyongyang agreed to give up its nuclear weapons program in exchange for two civilian nuclear power plants and shipments of fuel oil.

A North Korean Foreign Ministry spokesman said Thursday that a nuclear power plant closed in 1994 was being revived to meet power needs because of the U.S.-led decision last month to suspend oil shipments.

The Bush administration says it wants to solve the problem through diplomacy involving South Korea, Japan, China, Russia and the European Union. But the White House also has insisted that North Korea agree to give up its nuclear program as a precondition, something Pyongyang has angrily insisted it will not do.

Intercepting the shipment of 15 North Korean-made Scud missiles apparently is an attempt by the Bush administration to turn up the heat on Pyongyang, said Joel Wit, who helped negotiate the 1994 agreement as a State Department official.

"We've kind of made an effort to halt these relationships, but nothing along the lines of intercepting a ship on the high seas," said Wit, now an analyst with the Center for Strategic and International Studies. "I'm sure the administration is doing a lot of things to build international support in opposition to North Korea's uranium enrichment. Another thing they can do is cut North Korea off from overseas buyers of its weapons."

Defense Secretary Donald H. Rumsfeld has said he believes North Korea has one or two nuclear weapons already and called the irascible communist regime the world's worst proliferator of missiles and missile technology. Besides Yemen, North Korea's missile customers include Libya, Iran, Syria, Pakistan and Egypt.

But U.S. officials were forced to acknowledge after American forces boarded the North Korean vessel that the deal with Yemen was legal and stopping it would have violated international law.

"We have no choice but to obey international law," White House spokesman Ari Fleischer said. "What Yemen has done ... does not provide a threat to the United States. We do have ongoing concerns about North Korea's efforts to sell arms around the world."

Some critics say Bush's public commitment to a diplomatic solution in North Korea — a country he branded part of an "axis of evil" with Iraq and Iran — contradicts his policy of threatening military action if Iraqi President Saddam Hussein does not give up his weapons of mass destruction.