Head of the UN nuclear watchdog Mohamed ElBaradei says Israel has expressed concern over Iran's nuclear ambitions.
Mr ElBaradei played down prospects of Israel revealing nuclear secrets
He was speaking after holding talks at Israel's Atomic Energy Commission, before meeting Prime Minister Ariel Sharon on Thursday.
Mr ElBaradei is in Israel as part of a push for a nuclear-free Middle East.
Hours before his arrival, Mr Sharon said Israel would continue with its policy of neither confirming nor denying it has nuclear weapons.
Iran, which unlike Israel has signed the nuclear
Non-Proliferation Treaty (NPT), says it wants nuclear technology for peaceful purposes.
But Washington and Israel accuse Tehran of secretly trying to develop nuclear weapons.
Late in 2003, the head of Israel's intelligence service, said that the Iranian nuclear programme represented the greatest ever threat to Israel.
'Need for dialogue'
Meanwhile, Mr ElBaradei played down the prospects of being able to persuade Israel to reveal its own nuclear secrets during his visit to the country.
But he told reporters he wanted to see "the beginning of a dialogue on how a... nuclear security free zone could look".
"If I get the parties closer on the need for a dialogue, I think I'll be successful," he said.
He said he hoped to persuade Israel to sign up to some agreements with International Atomic Energy Agency on exports and imports of nuclear-related material.
Israel is widely believed to have a large stockpile of nuclear warheads, but refuses to confirm or deny that it has a nuclear deterrent.
'Policy of ambiguity'
Before Mr ElBaradei's visit, Israel released photos of its nuclear plant in the Negev desert for the first time.
The images appear on a new website for the Israeli Atomic Energy Commission. Analysts believe Israel has about 200 warheads at the plant in the town of Dimona.
Mr ElBaradei was not scheduled to visit any Israeli nuclear facilities.
Mr Sharon, quoted by Israeli Army Radio, said the country did not intend to change its "no show, no tell" policy of nuclear ambiguity.
"I don't know what he [ElBaradei] is coming to see," Mr Sharon said.
"Israel has to hold in its hand all the elements of power necessary to protect itself by itself.
"Our policy of ambiguity on nuclear arms has proved its worth, and it will continue," Mr Sharon added, without elaborating.
In December, Mr ElBaradei urged Israel - a member of the IAEA - to surrender its alleged nuclear weapons.
But, unlike Iran and North Korea - two nations whose alleged nuclear ambitions have recently come under international scrutiny - Israel has never signed the Nuclear Non-Proliferation Treaty, designed to prevent the global spread of nuclear arms.
As a result, it is not subject to inspections or the threat of sanctions by the IAEA.
Sharon said Israel would not change its "no show, no tell" policy
With a programme dating back to the early 1950s, Israel is widely believed to have become a fully-fledged nuclear armed power.
When compared with India and Pakistan - other states that have relatively recently developed nuclear arms - Israel's deterrent is probably the most sophisticated, our correspondent says.
It can be delivered by long-range ballistic missiles or advanced warplanes. Some reports suggest that Israel is even developing a submarine launched missile that might carry a nuclear warhead.