Iran has begun military exercises simulating a defense against any attack on its nuclear facilities. The United States and Israel have not ruled out a military option should negotiations over Tehran's nuclear program fail.
A top official in the Islamic Revolutionary Guard Corps downplayed the threat of any Israeli attack.
Speaking Sunday on the first day of the drills, General Amir Ali Hajizadeh said even if Israeli warplanes evade Iranian defenses, Iran will launch surface-to-surface missiles to destroy Israeli air force bases.
The five days of air defense drills are massive - covering more than half a million square kilometers. Officials say the military is trying out new weapons systems and testing whether its communications links can withstand electronic warfare.
Iranian media gave prominent coverage of the war games, which the military says are its biggest ever.
The exercises coincide with increasing tensions over a deal meant to ease western concerns Iran could be pursuing nuclear weapons, which Tehran denies. Iranian officials have raised objections to the offer by the International Atomic Energy Agency to enrich Iran's uranium abroad.
World powers are searching for tougher options, including more sanctions, to force Iran's hand.
Israel, along with the United States, has kept open the possibility it could strike Iranian nuclear facilities if the issue is not resolved.
In Cairo, Israeli President Shimon Peres rejected the idea that it is up to his country to ease tensions by agreeing to sign the Nuclear Non-Proliferation Treaty. Israel is widely suspected of having nuclear weapons.
"Israel said we shall not introduce nuclear weapons to the Middle East," Mr. Peres said. "And I know there are suspicions, but if suspicion postpones war, let them suspect. We do not threaten anybody. We are not an enemy of anybody. The Iranians are not our enemies. We are against the present leadership of Iran, which is very aggressive and denies the Holocaust and says publicly they want to wipe out Israel from the map."
Mr. Peres noted that Iran signed the non-proliferation treaty, and said "It is not worth a penny."