UN nuclear watchdog chief Mohamed ElBaradei has called for the start of talks on a global treaty banning the production of nuclear materials for weapons.
"It is essential that we take steps to eliminate both access to and production of material for nuclear weapons," Mr ElBaradei, the director-general of the International Atomic Energy Agency, told the UN General Assembly.
The assembly called in 1993 for negotiation of such a pact - also known as the Fissile Material Cut-off Treaty.
Talks have never gotten off the ground, and last July the Bush administration said it no longer wanted verification measures in the treaty because they would be too costly and unreliable.
Mr ElBaradei, who was presenting the IAEA's annual report to the 191-nation UN assembly, also expressed disappointment that neither last May's Non-Proliferation Treaty review conference nor last month's World Summit reached any new agreements on measures to curb the spread of atomic arms and promote disarmament.
Among his agency's top priorities for the coming year is to convince North Korea, which has pulled out of the Non-Proliferation Treaty, to return to the treaty's control regime, and to obtain assurances from Iran about the goal of what Tehran insists is a peaceful nuclear programme.