Iranian army chief Amir Hatami on Saturday warned the United States and Israel against an attack, saying his country's forces were on high alert.
He also insisted Iran’s nuclear expertise could not be eliminated, after US President Donald Trump said he expected Tehran to seek a deal to avoid US strikes.
"If the enemy makes a mistake, without a doubt it will endanger its own security, the security of the region, and the security of the Zionist regime," Hatami said, according to the official IRNA news agency.
According to AFP, he noted that Iran's armed forces were "at full defensive and military readiness".
Washington sent a naval strike group to the Middle East led by the USS Abraham Lincoln aircraft carrier, with Trump threatening to intervene militarily after a deadly crackdown by Iranian authorities on two weeks of anti-government protests.
The deployment has raised fears of a possible direct confrontation with Iran, which has warned it would respond with missile strikes on US bases, ships and allies -- notably Israel -- in the event of an attack.
On Friday, Trump said he predicted that Iran would seek to negotiate a deal over its nuclear and missile programs rather than face American military action.
Iranian Foreign Minister Abbas Araghchi had said earlier that Tehran was ready for nuclear talks, but its missiles and defense "will never be negotiated".
The US carried out strikes on key Iranian nuclear sites in June when it briefly joined Israel's 12-day war against its regional foe.
Israeli attacks also hit military sites across the country and killed senior officers and top nuclear scientists.
But Hatami on Saturday insisted that Iran's nuclear technology "cannot be eliminated, even if scientists and sons of this nation are martyred".
On Friday, US Central Command (CENTCOM) said Iran's Revolutionary Guard Corps (IRGC) would conduct "a two-day live-fire naval exercise" in the Strait of Hormuz, a key transit hub for global energy supplies.
In a statement, CENTCOM warned the IRGC against "any unsafe and unprofessional behavior near US forces".
Nationwide protests against the rising cost of living erupted in Iran on December 28, before turning into a broader anti-government movement that peaked on January 8 and 9.
Iranian authorities have said the protests began peacefully before turning into "riots" involving killings and vandalism, blaming the United States and Israel for fomenting the unrest in a "terrorist operation".
The official death toll from the authorities stands at 3,117.
However, the US-based Human Rights Activists News Agency (HRANA) said it has confirmed 6,563 deaths, including 6,170 protesters and 124 children.
The protests have since subsided.
