A senior Iranian military official warned the United States against launching any attack on the Islamic Republic, a news agency reported on Monday, two days after the United Nations imposed new sanctions on Iran.
"If America starts a war against Iran, it won't be the one who finishes it," Morteza Saffari, naval forces commander of the elite Revolutionary Guards, was quoted as saying by the ISNA news agency.
"Our people will not even allow one American soldier to enter our country," Saffari said.
International tension over Iran's disputed nuclear program has risen in recent days, sending oil and gold prices higher. The West suspects Iran is seeking to make atom bombs, a charge Tehran denies.
Iran said on Sunday it would limit cooperation with the UN's nuclear watchdog and vowed not to halt its atomic program "even for one second" after the Security Council voted to impose new arms and financial sanctions on Tehran.
On Friday, Iran's Revolutionary Guards seized 15 British navy personnel in the Gulf, sparking a diplomatic crisis.
The United States, which is leading efforts to isolate Iran over its nuclear ambitions, has said it prefers a diplomatic solution to the crisis but has not ruled out military options.
"We have the spirit of resistance and this is a factor to stop (them)," Saffari said.
"Our nation's unity and martyrdom-seeking spirit with God's help is always a guarantee for the Islamic Iran's resistance."