Prime Minister Benjamin Netanyahu said Tuesday after world powers reached a historic nuclear deal with Iran that Israel was not bound by it and signalled he remained ready to order military action.
Netanyahu's harsh criticism of the agreement came after he warned for months that the deal being negotiated would not prevent Iran from acquiring nuclear weapons.
While analysts say unilateral military action by Israel seems unlikely for now, Netanyahu and other officials have kept the option on the table.
"Israel is not bound by this deal with Iran, and Israel is not bound by this deal with Iran because Iran continues to seek our destruction," Netanyahu told reporters before a meeting of his security cabinet.
"We will always defend ourselves."
Netanyahu called the nuclear deal a "historic mistake", and the accord drew strong criticism from across the Israeli political spectrum.
"We did commit to preventing Iran from acquiring nuclear weapons, and this commitment still stands," Netanyahu said earlier on Tuesday, even before the agreement was officially announced.
He has taken his campaign to the US Congress and the UN General Assembly, but ultimately failed to block the agreement.
The deal puts strict limits on Iran's nuclear activities for at least a decade and calls for stringent UN oversight, with world powers hoping that this will make any dash to make an atomic bomb virtually impossible.
In return, painful international sanctions that have slashed the oil exports of OPEC's fifth-largest producer by a quarter and choked its economy will be lifted and billions of dollars in frozen assets unblocked.
"You can't prevent an agreement when those negotiating it are prepared to make more and more concessions to those shouting 'Death to the United States' even as the talks are in progress," Netanyahu said.
"Iran will get hundreds of billions of dollars with which it will be able to fuel its terror machine," he said, referring to the expected lifting of sanctions.
Defence Minister Moshe Yaalon accused the six powers that negotiated the deal -- Britain, France, the United States, Germany, China and Russia -- of needlessly caving in to Tehran.
"Iran, who arrived at the negotiating table in a weak position, has emerged victorious," he said.
"Instead of fighting terror with all its might, the free world has granted legitimacy to Iran's hateful, murderous ways. This agreement is a tragedy for all who aspire for regional stability and fear a nuclear Iran."
Late on Monday, Netanyahu even opened a Persian-language Twitter account, @IsraeliPM_Farsi, to rail against the deal in the hope of convincing the Iranian public.
Opposition leader Isaac Herzog said on his Facebook page that "Israel's interests have been abandoned".
Science and technology minister Danny Danon said it was "not just bad for Israel, it's dangerous for the entire free world".
"Giving the world's largest supporter of terrorism a free pass in developing nuclear weapons is like providing a pyromaniac with matches," he said in a statement.
Deputy foreign minister Tzipi Hotovely called the deal "a capitulation of historic proportions to the Iran-led axis of evil".
"The implications of this agreement for the foreseeable future are very grave," she said.
"The state of Israel will employ all diplomatic means to prevent confirmation of the agreement."
In New York, World Jewish Congress president Ronald S. Lauder was more cautious.
"We are still looking forward to getting all the details of this agreement, with the hope that the verification process will allow inspectors to determine Iran's true aims," the WJC quoted him as saying.
"As the famous proverb goes, 'The road to hell is often paved with good intentions'."