A panel of experts on North Korea told US lawmakers Wednesday that Pyongyang will probably conduct a new nuclear test, and relying on China to dissuade the isolated state from doing so is unwise.

"It's not unreasonable to expect that in the next few months we will see, based on the historical pattern, a nuclear test," said Dr Michael Green, an analyst at the Washington-based Center for Strategic and International Studies (CSIS) think tank.

"The pattern fits," he told members of the House of Representatives Committee on Foreign Affairs, referring to missile tests carried out by the isolated North in 2006 and 2009, ahead of nuclear tests later in those years.

North Korea's nuclear intentions are under the microscope following a failed rocket launch last week that was widely condemned. The United States suspended a recently agreed food aid deal with the impoverished state over the launch.

Frederick Fleitz, a former CIA officer and ex-State Department official on arms control, said that the chances of a nuclear test "are less than 50-50 right now," but it was nevertheless likely in the future.

"I think there will be a nuclear test eventually when North Korea is technically ready and prepared to endure the enormous amount of isolation it will endure," said Fleitz, who now heads up the Langley Intelligence Group Network, an intelligence forecaster.

"Frankly all bets are off with this country," he said, while stressing that he thought ballistic missile tests "are certain."

"The missile test may be more threatening because the missile test could land on Japan, it could land on Hawaii, it threatens the west coast of the United States and it is the delivery system for a nuclear weapon," he said.

North Korea warned of retaliation after the US confirmed it had scrapped food aid in the wake of last week's rocket launch.

China, the North's main ally has urged all "relevant parties" to "exercise calm and restraint, maintain engagement and dialogue and continue to uphold the denuclearization process on the Korean peninsula."

But Scott Snyder, a senior fellow for Korea Studies and director of the program on US-Korea Policy at the Council on Foreign Relations, said relying on Beijing to intervene was unlikely to yield results.

"It's very clear that the Chinese have their own interests in promotion of North Korean stability and this is creating a gap in expectations," he said.

"We shouldn't be relying on China as a way of trying to pursue our approach to North Korea."

Tying nuclear concessions to food aid "was a mistake," he added.

China calls for calm after N. Korea threats
Beijing (AFP) April 18, 2012 - China urged calm and restraint Wednesday after North Korea warned of retaliation over the United States' suspension of much-needed food aid following Pyongyang's recent failed rocket launch.

In a defiant statement late Tuesday, the isolated nation also broke off an agreement with Washington to halt testing of nuclear weapons and long-range missiles, raising fears Pyongyang would stage a new atomic test.

"We believe that maintaining peace and stability on the Korean peninsula is in the interest of all parties ... Dialogue and negotiation is the only correct way out," foreign ministry spokesman Liu Weimin told journalists.

"We hope relevant parties will exercise calm and restraint, maintain engagement and dialogue and continue to uphold the denuclearisation process on the Korean peninsula."

The North on Friday went ahead with what it said was a rocket launch to put a peaceful satellite into orbit, drawing condemnation from world leaders who said the exercise was a disguised ballistic missile test.

The launch quickly failed when the rocket exploded over the Yellow Sea, and the United Nations Security Council on Monday issued a condemnation that was also backed by China -- the North's only major ally.

Analysts say they expect the North to now stage a third nuclear weapons test, following previous tests in 2006 and 2009, or launch another long-range missile.

Liu urged the International Atomic Energy Agency to resume contact and dialogue with North Korea in the apparent hope the two could seek a way forward for the UN atomic agency to inspect North Korean nuclear facilities.

But he would not comment on reports that Beijing has suspended a deal with Pyongyang to repatriate North Korean refugees who had fled to China because it was not consulted about the launch.