Iran's top security body said it had obtained intelligence about Israeli nuclear sites and could launch counterattacks in the event of an attack by Israel.
Israel has repeatedly warned it could attack Iranian nuclear plants, particularly if US-Iran talks were to collapse.
An intelligence trove that Iran claimed it had obtained "would enable the fighters of Islam to immediately strike [Israel's] hidden nuclear facilities in response to any possible attack by the Zionist regime on Iran's nuclear facilities," the Supreme National Security Council said.
It added that it would respond in a "precisely proportional" way if Israel struck.
Iran's Minister of Intelligence Esmail Khatib had said a day prior that his department has "an important treasury of strategic, operational and scientific intelligence" belonging to Israel, which he said was "transferred into the country with God's help”.
Israel is widely assumed to possess atomic weapons but maintains a policy of "nuclear ambiguity" by neither confirming nor denying their existence. The Stockholm International Peace Research Institute, which tracks nuclear stockpiles, estimates that Israel has 90 warheads.
The strong Iranian rhetoric comes as a sixth round of talks is expected to take place this week. US President Donald Trump said the dialogue would held be on Thursday while Iran offered Sunday as a date.
Mr Trump and Israeli Prime Minister Benjamin Netanyahu held a 40-minute phone call on Monday evening, shortly after Iran announced that it would soon respond to Washington’s latest proposal for a nuclear deal.
Following the call, Mr Netanyahu held a high-level security consultation focused on Iran.
The Prime Minister’s Office said the two leaders discussed Washington’s nuclear talks with Tehran.
“President Trump told the Prime Minister that the United States has presented a reasonable proposal to Iran and is expected to receive its response in the coming days,” the Israeli Prime Minister's office said.
