Iran can deter any threats against it, the head of the Revolutionary Guards said in comments published on Wednesday, after the country's air force announced plans for a military exercise to help deter its foes.
Iran is embroiled in a deepening international standoff over its nuclear programme, which the United States and Israel suspect is aimed at making bombs, a charge Tehran denies.
In a shift in policy the United States will send a senior envoy, Under Secretary of State William Burns, to talks between Iran and major powers this weekend to discuss Tehran's response to an offer of incentives if it suspends enriching uranium.
Washington had said previously it would not be involved in pre-negotiations with Tehran unless it gave up enrichment.
"The enemies of Iran would not dare to undertake any direct threat or any other action against Iran," Iran's Revolutionary Guards commander-in-chief Mohammad Ali Jafari was quoted as saying by the official IRNA news agency.
U.S. leaders have not ruled out military options if diplomacy fails to assuage fears about Iran's nuclear activities, which the world's fourth-largest oil producer says is only to produce electricity.
Israel, long assumed to have its own atomic arsenal, has vowed to prevent Iran from emerging as a nuclear-armed power. It staged an air force exercise in June that stoked speculation about a possible assault on Iranian nuclear sites.
But Iran has refused to halt sensitive nuclear work, as demanded by the powers before formal negotiations can begin on a package of trade and other benefits they have offered to Tehran.
Tension increased further last week after Iran test-fired missiles in the Gulf, including one it says could reach the Jewish state and U.S. bases in the Middle East.
Fears of conflict helped to push oil prices to new record highs last week, although prices fell $6 on Tuesday to around $138 a barrel amid growing concerns about the U.S. economy.
