Pakistan President Pervez Musharraf is considering sending nuclear parts to a UN watchdog to help it investigate if Iran is developing atomic weapons.
Critics ask why fuel-rich Iran needs nuclear energy
Pakistan admits its disgraced scientist AQ Khan gave Iran nuclear centrifuges.
The centrifuges help produce enriched uranium that can be used for nuclear weapons or in power plants.
The International Atomic Energy Agency found traces of uranium in Iran's equipment, which Tehran blamed on the second-hand Pakistani centrifuges.
Earlier this month, Pakistan denied reports from sources close to the UN inquiry into Iran's nuclear programme that it would hand over the uranium-enriching components to inspectors.
But now Gen Musharraf has told the Aaj television channel that Pakistan was considering a "one-off" offer to co-operate, either by sending parts to the IAEA in Vienna or hosting its inspectors in Pakistan.
"We are considering and negotiations are under way and we will see," he said.
"We have said, 'OK, we will give you them and you examine them outside, or maybe you [come] to us'. But once and for all, and after that, we've told them that once we do it, then don't ask next time."
The BBC's Zaffar Abbas in Islamabad says the move is apparently aimed at clearing Pakistan's name in the controversy surrounding Iran's nuclear programme.
The IAEA has been investigating Iran's programme for more than two years.
AQ Khan - still a hero to many Pakistanis
It is still trying to verify whether, as Tehran says, Iran's nuclear ambitions are purely peaceful.
The US accuses Iran, a state already rich in gas and oil, of pursuing atomic energy as a screen to develop nuclear weapons.
Only last week, Pakistan's foreign ministry rejected the suggestion Pakistan would hand over technology for inspection as baseless.
"Pakistan has not been asked to give centrifuges, nor will Pakistan do so," Jalil Abbas Jilani told reporters.
On her trip to Pakistan last week, US Secretary of State Condoleezza Rice pressed Pakistan to tell Washington everything it knew about the AQ Khan nuclear weapons-smuggling network.
Pakistan has admitted Dr Khan led an international network that was involved in transferring nuclear information and material to countries like Iran, Libya and North Korea.
Since this public confession, Dr Khan has remained under house arrest.
However, he remains a hero to many Pakistanis and has received a presidential pardon.
Pakistan has so far refused to allow foreign investigators to interrogate Dr Khan.