Iran will attack “the heart of Israel” if it makes the slightest move against Iranian interests, President Ebrahim Raisi told a military parade on Monday.
Mr Raisi spoke as talks stalled in Vienna over a deal to rein in Iran’s nuclear capabilities, which Tehran says are for energy and medical purposes.
“The Zionist regime, you should know that … if you take the slightest move against our nation, our armed forces will target the heart of the Zionist regime,” Mr Raisi said in a televised speech at a military parade to mark National Army Day.
Israel, widely believed to have the Middle East's only atomic arsenal, says it will not be bound by any Iran nuclear deal and could eventually take unilateral action against Iranian nuclear sites.
Mr Raisi said Iran watches any move by Israel “closely”.
Iran has not recognised Israel since the 1979 Islamic Revolution that ousted the pro-West monarchy and brought Islamists to power.
Tehran supports anti-Israeli extremist groups such as Hamas and Hezbollah.
Iran's military had managed to improve its capabilities, despite years of sanctions imposed on the country over its nuclear programme, Mr Raisi said.
He said that Iran’s military power is a deterrent.
Monday’s parade featured jet fighters, helicopters, drones and air defence systems, plus tanks, missiles and naval vessels.
Israel has improved relations with some Arab countries, which has angered Iranian leaders.
Tehran blames Israel for the sabotage of its nuclear sites and the assassinations of its nuclear scientists.
In 2015, Iran and major world powers signed the Joint Comprehensive Plan of Action, under which Tehran would reduce its nuclear stockpile in return for sanctions being eased.
The deal collapsed four years ago when Donald Trump, US president at the time, withdrew his country and imposed tough sanctions on Iran. Talks in Vienna have been aimed reviving the JCPOA.
In the meantime, Iran has expanded its nuclear work. US intelligence agencies and nuclear watchdog the International Atomic Energy Agency believe Iran had an organised military nuclear programme until 2003.