Washington is the chief sponsor of the protracted talks designed to wean North Korea away from its nuclear program and defuse the crisis in the Korean peninsula.

But the parties to the talks -- the two Koreas, the United States, Japan, Russia and China -- are divided on how to reward and reign in Pyongyang, which last week spurned talks and made an unambiguous declaration it is a nuclear weapons state.

The United States has told the other participants that any assistance pledged to cash-starved North Korea cannot be given until it fully discloses upfront its nuclear program. North Korea wants a step-by-step aid-for-disclosure program.

Washington has distanced itself from an energy aid program for North Korea which China, Russia, South Korea and Japan have agreed to under a proposal introduced at the talks.

The administration of President George W. Bush is also against any one-on-one talks with North Korea outside the six-party process and has refused to give any indvidual security guarantee to North Korea, for whom nuclear arms is the only bargaining chip.

Compounding the problem are divisions within the Bush administration -- which is focused on Iraq -- on how to deal with North Korea.

China and South Korea meanwhile have refused to use their economic might against the Stalinist regime, which relies heavily on them for investments and trade.

"The time has come for the other five (parties) finally to begin speaking with one voice to Pyongyang, to hold it accountable for its own words and actions," said Ralph Cossa of the US Center for Strategic and International Studies.

He said that following the flexing of North Korea's nuclear muscle last Thursday, China should call an emergency plenary session of the six-party talks, inviting Pyongyang to attend and provide further explanation of its current stance.

"If North Korea receives conflicting signals from Washington, Seoul, Beijing, Tokyo, and Moscow in the face of this latest provocation, it will be encouraged to continue this divide and conquer tactic," Cossa said.

Furthest away from the crisis flashpoint and having seen North Korea renege on a bilateral deal for ending its nuclear arms program, the United States has the "least pressing need to deal with the problem and yet it is absolutely vital for any breakthrough," said US think tank Strafor's Korea expert Rodger Baker.

He said for the hardline communist regime, the United States is the key to any resolution to the nuclear crisis because Washington was a signatory to an armistice that followed the bloody 1950-1953 war between the two Koreas.

The two Koreas today remain technically at war -- in which the south was backed by US-led forces -- because the conflict ended in an armistice rather than a peace treaty.

"The US signed the armistice, the South Koreans didn't, the Japanse didn't and so, the US from the North Korean point of view is the main military threat to them," Baker said.

Leading US dailies have called for a review of the US policy on North Korea.

The Washington Post said "the Bush administration needs to rethink its own failing policy," noting that Pyongyang had been trying, with some success, to convince its neighbors that the United States was "the obstacle to progress because of its refusal to offer the North greater concessions."

To achieve diplomatic success, the paper called for "more determined action by North Korea's neighbors and an unambiguous decision by the Bush administration to settle for detente with the North, rather than regime change."

Aside from the need for a change in attitude by North Korea, the New York Times suggested "a drastic change of approach by the United States" to end the Asia-Pacific region's most serious deadlock.

The Bush administration did not create this problem, the paper said, "but, with a series of avoidable errors, it has made it much worse, much faster than might otherwise have been the case."

Bush had, after the deadly September 11, 2001 terror attacks on the United States, termed North Korea an "axis of evil" together with Iraq and Iran.

"The strategy of listing North Korea as one of three partners in an axis of evil and then proceeding to invade the partner that was furthest away from a nuclear weapons program was no way to persuade North Korea to give up its nuclear deterrent," the paper said.

In addition, Washington's nonproliferation diplomacy had also been handicapped by the Bush administration's double standards about the nuclear proliferation offenses of Pakistan and other allies.