Senate Democrats accused the Bush administration yesterday of failing to stem North Korea's nuclear threat, even as White House officials said they were using all available diplomatic avenues to block the communist nation from developing nuclear weapons.

In a news conference with former Clinton administration officials, several senators suggested that President Bush had essentially acquiesced to North Korea's drive to develop a nuclear bomb.

"The White House continues to sit back and watch, playing down the threat and apparently playing for time," said Senate Minority Leader Thomas A. Daschle (D-S.D.). "But time is not on our side." Other speakers included former defense secretary William J. Perry, former secretary of state Madeleine K. Albright and former national security adviser Samuel R. "Sandy" Berger.

Perry described Korea as "the most dangerous spot in the world today."

"We cannot wait this out," Perry said. "In a few months, the North Koreans will have five or six nuclear bombs. That fundamentally changes the situation."

Later in the day in a Senate floor speech, Sen. Robert C. Byrd (D-W.Va.) said: "I am increasingly alarmed that this administration's military and diplomatic fixation on waging war with Iraq is serving to overshadow and possibly eclipse the mounting crisis in North Korea."

White House officials said they were determined to halt the development of nuclear weapons despite published reports, including one in The Washington Post, saying the administration and several Asian governments were resigned to North Korea's developing nuclear arms. The reports suggested the administration primarily was seeking to prevent Pyongyang from selling nuclear material abroad.

Bush spokesman Ari Fleischer said the United States and its allies were working "to make certain that there is a denuclearized [Korean] peninsula. And that's why we're working so hard on this, and why we have called directly and publicly for North Korea to dismantle its nuclear programs."

Fleischer declined to say whether the administration would consider the reprocessing of fuel in a North Korean reactor crossing "a red line."

"But, obviously, what is important here is for North Korea to recognize the damage it is doing to itself, the economic harm that it brings on its own people, who are among the poorest and the most isolated and the most hungry in the world, as a result of a country that diverts its few resources away from the people and toward the military," he said. "And what's important is that they dismantle the program, that they not engage in further provocative or reckless actions."

Tensions between the United States and North Korea escalated this week after North Korean jets intercepted and shadowed a U.S. reconnaissance plane over the Sea of Japan.