Israel has accused North Korea of supplying at least half a dozen Mideast governments with nuclear technology or conventional arms.

World powers at a 145-nation Vienna meeting of the International Atomic Energy Agency at the same time urged North Korea to stop reactivating its weapons-producing atomic programme.

The comments focused on North Korea's black market role and its reversal of a commitment to mothball its nuclear activities in exchange for trade and security guarantees.

In the latest setback, US chief negotiator Christopher Hill returned Friday to South Korea from a three-day trip to the North to try to salvage a six-party disarmament pact after North Korea reversed the dismantling of its nuclear facilities. He was hoping to draw the government in Pyongyang back to the negotiating table with an offer of a face-saving compromise.

US State Department spokesman Robert Wood in Washington told reporters the North was still moving previously stored equipment from its nuclear facilities back to its original location.

In Vienna, Russia, China, Japan and South Korea urged the North to honor its nuclear pledge, shortly before the gathering — the IAEA general conference — passed a resolution expressing the same sentiments.

North Korea's actions "will cause serious consequences to the prospect of the six-party talks," a South Korean statement said, referring to North Korea and the five nations engaging it on the nuclear issue — the US, Japan, South Korea, China and Russia. Japan expressed "serious concern" about the North's moves and urged it to return to the terms of its disarmament for aid deal with the other five countries.

Separately, Israeli delegate David Danieli accused North Korea of being a black market supplier of conventional arms or nuclear technology to Middle East nations covertly trying to break out of the nonproliferation fold.

While he did not name the "at least half dozen" countries suspected of accepting the North's help, he appeared to be referring in part to Iran and Syria, which are both under IAEA investigation.

Israel — which is widely considered to have nuclear weapons — refuses to either confirm or deny its status.

Besides Iran, Syria and Libya, US officials have said that North Korea's customer list for missiles or related components going back to the mid-1980s includes Egypt, the United Arab Emirates and Yemen.

U.S. government officials have also said that A.Q. Khan — the Pakistani scientist who confessed in 2004 to running an illegal nuclear market — had close connections with North Korea, trading in equipment, facilitating international deals for components and swapping nuclear know-how.

In 2004, the CIA director at the time, George Tenet, testified before Congress that North Korea had shown a willingness +to sell complete systems and components; for missile programs that have allowed other governments to acquire longer-range missiles.

Concerns about Iran focus on its refusal to scrap a secretly developed uranium enrichment program that could be retooled to produce fissile warhead material if Tehran were to choose that path. Tehran is also suspected of hiding past efforts to develop a nuclear weapons program.

Syria surfaced on the IAEA's radar screen after Israeli warplanes last year destroyed what the U.S. says was a reactor of North Korean design that — when completed — was meant to produce plutonium. Both Syria and Iran — which is under U.N. sanctions for its nuclear defiance — deny having weapons ambitions.

Diplomats have said that the IAEA has been forwarded intelligence that outlines years of extensive cooperation between the Syrians and teams of visiting North Korean nuclear officials.

Western intelligence agencies also have reported that Iran's Shahab-3 missile is based on a North Korean rocket, though Tehran denies it.

According to US officials and outside experts, North Korea has sold its military goods to at least 18 countries, mostly in Africa and the Middle East.

North Korea's catalog has included ballistic missiles and related components, conventional weapons such as mobile rocket launchers, and nuclear technology.

North Korea had been disabling its nuclear facilities at its Yongbyon complex but abruptly stopped in mid-August, citing Washington's refusal to remove it from a list of state sponsors of terrorism.

The disarmament process snagged over Washington's request that North Korea agree to a verification system to account for its nuclear arsenal as a condition for removing the country from the terrorism list.

North Korea exploded a nuclear device in 2006.

Times Recommends

• Google to digitise Iraqi artefacts
• Renault angers parents by naming new car Zoé
• Analysis: most lawless part of Philippines