Israel will stay silent on its assumed nuclear capabilities despite international calls for inspection, Prime Minister Ariel Sharon said on Thursday.
"Our policy of 'nuclear ambiguity' has proven itself and will be sustained," Sharon told Army Radio.
Keen to ward off regional foes but avoid sabre-rattling, Israel neither confirms nor denies pursuing weapons of mass destruction.
Analysts believe Israel has produced as many as 200 warheads at a secret reactor near the desert town of Dimona, which it has kept exempt from international inspections by not signing the nuclear non-proliferation Treaty (NPT).
International Atomic Energy Agency (IAEA) chief Mohamed ElBaradei, one of those pushing Israel to sign, is to visit in July for what officials called a routine tour of Israeli facilities - but not Dimona.
Sharon did not discuss ElBaradei's visit, but described the IAEA as part of efforts to track an Iranian nuclear programme Israel views as a threat. Tehran denies having hostile designs.
"We are certainly in contact with him (ElBaradei), and we are monitoring, with concern, Iran's efforts to obtain nuclear arms," Sharon said.
Against frequent protests from Iran and the Arab world, Israel's chief ally, the United States, tacitly backs its refusal to sign the NPT under an agreement dating back to 1963.
Sharon hinted that US President George W. Bush reiterated the understanding this month as part of his written endorsement for an Israeli plan to "disengage" from the Palestinians.
"In the deal between myself and the Americans - and this appears in President Bush's letter - it was said explicitly that Israel must be properly prepared to defend itself from outside threats, and to maintain all the means necessary for this self-defence," Sharon said without giving details.