By JOHN HEILPRIN

UNITED NATIONS (AP) – The U.N. nuclear chief said Monday that Iran is blocking his watchdog agency from verifying whether the nation has any ambitions for nuclear weaponry.

“I regret that we are still not in a position to achieve full clarity regarding the absence of undeclared nuclear material and activities in Iran,” Mohamed ElBaradei, the head of the International Atomic Energy Agency, told the U.N. General Assembly.

He urged Iran to do more to ensure “transparency,” but emphasized the Vienna-based IAEA “does not in any way seek to pry into Iran’s conventional or missile-related military activities.”

Iranian Ambassador Mohammad Khazaee countered that the U.N. Security Council’s demand that his nation suspend uranium enrichment is “illegal.”

Iran’s nuclear program, he said, is only for peaceful purposes and designed to produce nuclear energy and the nation “will never accept illegal demands.”

Khazaee also said that the five permanent members of the Security Council – the U.S., Britain, China, Russia and France – plus Germany never responded to Tehran’s proposal that they negotiate without preconditions. The six powers have offered economic and political incentives if Iran suspends its enrichment work.

“The policy of few powers in insisting on suspension as a precondition for negotiations bears zero relation to realities and is an irrational and failed policy,” he said.

ElBaradei also told the General Assembly in his annual report that he hoped North Korea, which tested a nuclear device two years ago, would return to the Nuclear Non-Proliferation Treaty from which it withdrew in 2003 after expelling all IAEA inspectors from the country.

IAEA inspectors were allowed to use some monitoring equipment at North Korea’s Yongbyon nuclear complex earlier this month, based on a U.S. deal that revived disarmament negotiations.

“I naturally still hope that conditions can be created for the DPRK (North Korea) to return to the NPT soon and for the resumption by the agency of comprehensive safeguards,” ElBaradei said.

On Friday, U.N. Secretary-General Ban Ki-moon urged the world’s nuclear powers to start negotiations on eliminating nuclear weapons and begin talks to assure other nations they will not be attacked. ElBaradei also said it was time to move from resolution to action.

Last month, the Security Council unanimously approved a new resolution reaffirming previous sanctions on Iran for refusing to halt its uranium enrichment program and offering Tehran incentives to do so.

It resulted from a compromise between the United States and Russia to lead a new council effort to condemn Iran’s nuclear program, without introducing any new sanctions.

The brief resolution reaffirmed the three earlier Security Council sanctions resolutions, which imposed progressively tougher sanctions on Iran for refusing to halt its uranium enrichment program.

Existing sanctions include an asset freeze on 65 companies and individuals linked to Iran’s nuclear program, and a travel ban on five people associated with Tehran’s nuclear and ballistic missile programs.

The sanctions also include bans on Iranian arms exports, supplying Iran with materials and technology that could contribute to its nuclear and missile programs, and on trade in goods that have both civilian and military uses.

Enrichment can turn uranium into fissile material used in nuclear warheads, but it can also be used to generate power and is allowed under the Nuclear Non-Proliferation Treaty.