An Israeli scientist is calling for his country to end a decades-long silence over its reported nuclear weapons capability and open its nuclear reactor to inspection.

Uzi Even, a Tel Aviv University chemistry professor and former worker at Israel's Dimona reactor, said US President Barack Obama's campaign for global nuclear arms reduction is a sign of changing times and Israel must get in step.

"We could open Dimona to international inspection," the former member of parliament with the left-wing Meretz party told Israeli army radio on Monday.

Mordechai Vanunu, who also once worked at the top-secret Dimona plant, was jailed from 1986 to 2004 for passing what he said were details of its operations to Britain's Sunday Times newspaper.

Since his release in 2004, he has been subject to a parole order barring him from travel or contact with foreigners.

Israel is widely believed to have around 200 nuclear warheads, but has a policy of neither confirming nor denying that, a stance which it calls "nuclear ambiguity."

"The policy of nuclear ambiguity, by which we fool only ourselves and nobody else, is not good for us any more," Even said.

"It was good, effective and successful for close to 40 years, but over 40 years many things changed and now I am telling you clearly, this policy is no longer in our interest."

However, Israeli Defence Minister Ehud Barak told an Israeli parliamentary committee on Monday that no policy shift was planned and that he did not see one being forced upon Israel by Obama.

"I don't think there is a real danger or threat to Israel's traditional position, as it has been expressed over the years," he told the foreign affairs and defence committee.

"The link between us and the United States is more complex than it may appear."

Media reports have said that the United States agreed in 1969 that as long as Israel did not test a nuclear weapon or publicly confirm that it had one, Washington would not press it on the issue.

"The understanding we have with the United States and other countries for many years has been quite effective," Strategic Affairs Minister Dan Meridor told reporters on Monday. "It need not change."

He did not elaborate.

Egypt is leading non-aligned nations in a push to convene a conference next year on turning the Middle East into a zone free of nuclear weapons.

Meridor dismissed as unimportant reports that Egypt had tabled a motion on Israel's nuclear weapons status for a June meeting in Vienna of UN watchdog the International Atomic Energy Agency.

"From time to time this issue is raised at the IAEA and other places," he said. It's not the first time it's mentioned and it's not the first time we'll find a way, with the rest of the world, to deal with it."