Iranian foreign minister Mohammad Javad Zarif said that Israeli premier Benjamin Netanyahu’s comment at a security conference in Munich was “delusional thinking”.
Mr Netanyahu said on Sunday that the nuclear deal with Iran has emboldened Tehran to become increasingly aggressive in the Middle East. He warned that Iran should "not test Israel's resolve" as he showed the audience what he claimed was part of a downed Iranian drone.
Mr Zarif, appearing two hours later at the same Munich Security Conference, described Mr Netanyahu’s speech as “a cartoonish circus, which does not even deserve [the] dignity of a response”.
"I can assure that if Iran's interests are not secured, Iran will respond, will respond seriously. And I believe it would be a response that means people would be sorry for taking the erroneous action they did," he said.
Mr Zarif suggested Mr Netanyahu might be escalating tensions with Iran simply to distract from his domestic problems.
Denouncing what he said were Israel's "almost daily illegal incursions into Syrian airspace", Mr Zarif said Israel was trying "to create these cartoonish images to blame others for its own strategic blunders, or maybe to evade the domestic crisis they're facing”.
In an interview with NBC News during the security conference, Mr Zarif said that Israel's loss of a fighter jet to Syrian anti-aircraft fire this month showed that its military had "crumbled".
"For years, Israel has been attacking Syria, Lebanon, almost with impunity, and for once, after 30-some years, the Syrians were able to down one of its planes — and so the myth of the invincibility of Israel, of the Israeli military, has crumbled."
He also warned US president Donald Trump during the interview that withdrawal from the Iran nuclear deal would have affect the reputation of the US as an international partner.
"If this administration in the United States fails to respect the obligations that the United States government — not a person, not an individual, not an administration [but] the US government — on behalf of the United States undertook, then nobody will in the future even trust any government, including President Trump's, to sign an agreement with them because the next administration will have a free hand to violate it,” said Mr Zarif.
Mr Trump has expressed deep scepticism about the Iran nuclear deal that lifted sanctions against the country. He extended sanctions waivers in January but said he would not do so again when they come up for renewal in May unless his concerns are addressed.