An Iranian military truck carries parts of a S-300 air defence missile system during a parade on the occasion of the country's annual army day on April 18, 2018, in Tehran. (AFP photo)

TEHRAN, April 18 (Xinhua) -- Iranian President Hassan Rouhani on Wednesday hailed the army's "peaceful" role in the region as the country celebrated the National Army Day.

Iran's defense program has a peaceful nature and the Islamic republic has no intention to invade other countries, Rouhani said in a ceremony to mark the event.

Iranian President Hassan Rouhani delivers a speech during a parade on the occasion of the country's Army Day on April 18, 2018, in Tehran. (AFP photo)

Rouhani blamed foreign forces for the cause of insecurity in the region. "The invaders have nested in our region and have illegitimate presence,"he said.

"They (the west) invade the other country in the region without licence from the United Nations," he said in a reference to the recent U.S.-led aggression on Syria under the pretext of Syrian army's alleged use of chemical weapons.

"In a context where big powers use the terrorist groups as their tools in the region, we need to equip our armed forces with deterrent means," he added.

An Iranian military truck carries part of surface-to-air missiles during a parade on the occasion of the country's annual army day on April 18, 2018, in Tehran. (AFP photo)

To secure its territory, Iran will increase its deterrent power, and the country will not wait for any permission to produce the defensive weapons it needs, said Rouhani.

Iran's neighbors should be assured that the defensive power of Iran is not a threat to them, he said, adding that Iran's regional policy is based on friendly relationship with its neighbors.

In Tehran, different units of Iranian army staged parades in the ceremony to show the latest Iranian military achievements, especially those in missile and radar technology.

The home-grown missile systems of Kamin-2, Tabas and Sayyad, as well as air defense systems of S-300 and S-200, radar systems, tanks, armored vehicles were among the military hardware on show.

In the Persian Gulf and the Sea of Oman, a parade of Iranian warships and destroyers was also held by Iran's Navy forces.

Chief of Staff of Iran Armed Forces, as well as Air Force, and Navy, and the Islamic Revolution Guards Corps (IRGC) commanders attended the ceremony in Tehran.