The UN's chief weapons inspector says North Korea is presenting a serious challenge to attempts to limit the world's nuclear weapons.
Mohamed ElBaradei urged Pyongyang to readmit his inspectors
Mohammed ElBaradei, head of the International Atomic Energy Agency, says the body's inspectors must be allowed back into the country.
He called on North Korea to rejoin the Nuclear Non-Proliferation Treaty it left two years ago.
Mr ElBaradei also urged Iran to suspend its uranium enrichment programme.
His comments came in his annual report to the United Nations General Assembly.
He said he was "frustrated" that Pyongyang was refusing to take part in six-party talks on the dismantling of its nuclear programme.
He said the international community would be ready to respond to the North Koreans' economic and humanitarian needs, "but a prerequisite is for them to commit themselves
to full, verifiable, dismantlement of their weapons programme".
Even if the project were not to be dismantled, he said, North Korea should allow "a comprehensive verification by the IAEA to assure ourselves that this programme is exclusively peaceful".
On Iran, Mr ElBaradei said he thought Tehran would be willing to suspend uranium enrichment if Europe agreed to supply fuel for Iran's planned power plants.
Then, he said, there would be no need for Iran to enrich its own uranium.
"Whether that will be ultimately a total suspension, or
something else, I think this very much depends on the kind
of framework to be agreed with the Europeans," he said.
Talks between Iran and major European countries
On Sunday, Iranian parliamentarians approved a draft bill that would oblige the government to resume uranium enrichment, as it has said it will.
However, Iran's most senior nuclear negotiator, Hossein Mousavian, said a compromise
was still possible.
Mr ElBaradei also said he wanted nuclear inspections in Iraq to resume "as soon as the security situation