The Israeli Security Cabinet rejected the nuclear agreement between the major powers and Iran and said Israel was not bound by it.
The decision came at an emergency session of the cabinet convened by Israeli Prime Minister Benjamin Netanyahu shortly after the Iran nuclear deal was announced.
The hawkish premier, a hardliner on Iran, minced no words and spared no superlatives while heaping scorn on the deal.
Netanyahu described the agreement as a "bad deal" and a "historic mistake".
He said: "I come here from a discussion in the Security Cabinet. The cabinet unanimously rejected the major powers' nuclear agreement with Iran and it determined that Israel is not bound by it."
"The world's leading powers have gambled on our common future in a deal with the main financer and operator of global terrorism. This is a historic mistake! We were right when we said that the desire to sign an agreement was apparently stronger than anything else; therefore, we did not commit to prevent the agreement. We did commit to prevent Iran from arming itself with nuclear weapons - and this commitment stands."
After meeting opposition leader Isaac Herzog to discuss the situation, Netanyahu said: "At present there is one mission – to ensure that it (Iran) does not arm itself with nuclear weapons in the future. And at this time, in the face of such a mission, we cannot indulge in petty politics and false accusations."
"This is the time to unite and create a united front on a fateful issue for the future of the State of Israel. In any case, we will continue to defend ourselves by ourselves against all who threaten our destruction."
Meanwhile, editorials in newspapers have urged the government to actively consider pre-emptive strikes on Tehran.
Reflecting the political mood in Israel, several editorials have openly asked the government to strike Iran.
An analysis on the Jerusalem Post website says: "Strike sooner or never – pre-emptive strike on Iran harder once UN lifts sanctions."
Another one carried by Ynet news reads: "Iran nuclear deal puts military option back on table."