Bush administration efforts to achieve nuclear disarmament in North Korea (search) are not working and should be reconsidered, Senate Foreign Relations Committee members said Tuesday.

"The administration policy has been a failure," said Sen. Joseph R. Biden Jr. of Delaware, the ranking Democrat.

"Obviously, we've not seen progress here," said Sen. Chuck Hagel, R-Neb. "Something is not working."

Responding to the criticisms at a committee hearing, Assistant Secretary of State Christopher Hill said the administration believes that the six-party disarmament negotiation "is the way to go."

Because of a North Korean boycott, there have been no negotiations for the past year. But North Korea, in meetings with U.S. diplomats on June 3, said they were willing to resume the discussions.

U.S. intelligence officials and other analysts believe that North Korea could possess several nuclear weapons beyond the one or two the country has been thought to have had for years.

Hill acknowledged the longer the impasse persists, the greater the risk of nuclear proliferation by Pyongyang.

At the same time, he said, North Korea's boycott has meant that it cannot receive the economic and security benefits that a disarmament agreement would yield.

"If they are worried about their survival, they should think about another course," Hill said. International isolation is another price North Korea is paying for its refusal to disarm, he added.

Several senators mentioned the U.N. Security Council as a possible alternative to the six-party process (search). Hill declined to speculate on other measures the administration may be contemplating.

Biden said that as a result of the continuing impasse, "the confidence in our ability to ensure peace and stability in Northeast Asia has been shaken."

He said the administration, far from adopting a unified position, has been debating with itself over North Korea policy.

As examples of officials he said are not in step with officially stated policy, Biden cited Vice President Dick Cheney, Secretary of Defense Donald H. Rumsfeld and U.N. Ambassador-designate John Bolton (search).

Committee Chairman Richard Lugar said the U.S. partners in the six-nation process — South Korea, China, Japan and Russia — don't seem particularly willing to bring pressure to bear on North Korea.

Hill agreed that China "has been reluctant" to use the full range of economic and political pressures to force a North Korean retreat.