"Iran is the most powerful and independent nation in the world," Ahmadinejad told a military parade outside Tehran marking the Islamic republic's annual army day.
Ahmadinejad said all the branches of the armed forces would react forcefully in response to any attack against Iran's soil and boasted that no-one would dare to launch a strike on the country.
"The army, the Revolutionary Guards and the Basij (militia) will resist with force and coordination and respond strongly to the slightest aggression."
"I am proud to announce today that the Iranian nation's power is of an extent that no major power can dare jeopardize the security and interests of the Iranian nation."
To mark the occasion, dozens of Iranian fighter jets and other aircraft flew over the parade ground in a bid to show the power of the air force which has struggled for years under the effects of US sanctions.
Among the aircraft on display were US-made F4 and F-5 fighter jets whose construction goes back to the 1960s and 1970s when shah Mohammad Reza Pahlavi went on a massive military spending spree.
Also shown were several Saegheh fighter jets which Iran says is a entirely home-produced model but Western experts classify as a derivative of the F-5.
Iran's air force has been hit hard by the blanket US embargo imposed after the toppling of the pro-American shah in the 1979 Islamic revolution, and the country must work intensely to find spare parts to keep its fleet in the air.
Iran is at odds with the West over its disputed nuclear programme, which the United States and its allies fear could be used to make nuclear weapons. Iran insists it only wants to produce nuclear energy.
The United States — and its ally Israel which Iran does not recognise — have never ruled out a military strike against the Islamic republic although Washington insists it prefers diplomacy.
Iran has in recent weeks been engaged in an intensifying war of words with Israel after an Israeli minister warned Iran would be destroyed if it launched an attack against the Jewish state.
"If Israel takes such action against the Islamic Republic of Iran, we will eliminate it from the global arena," deputy army commander Mohammad Reza Ashtiani riposted Tuesday.
Ahmadinejad repeated his belief that the power of Iran meant the prevailing world order was set to be turned on its head.
"Thanks to the resistance of the Iranian people, the great powers have become bogged down. The region and the world must prepare for great changes and the disappearance of satanic powers."
