"Ali Larijani departs today (Monday) for Iraq and then Lebanon on a three-day visit, his first foreign trip since taking office last week," state television reported

Larijani will sign a bilateral security agreement in Iraq before heading to Lebanon, where he will meet senior Lebanese officials and figures.

His trip to Lebanon comes after Tehran expressed strong opposition to a Lebanese government plan to disarm Tehran's ally Hezbollah, a stance condemned by Beirut as a "flagrant and unacceptable interference".

"Our cooperation with the Lebanese government is long and deep. We consult on various regional issues. In this particular context, we are talking to Lebanese officials and influential figures in Lebanon," Larijani told state TV before departing.

"In Lebanon, our positions are already clear. Lebanese national unity is important and must be preserved in all circumstances. Lebanon's independence is still important to us and we will contribute to it."

On Saturday, Ali Akbar Velayati, a senior advisor to Iran's supreme leader, described the plan to disarm Hezbollah as compliance "to the will of the United States and Israel".

The disarmament push followed last year's war between Israel and Hezbollah, which left the group, once a powerful political and military force, weakened.

It also comes amid pressure from the United States and anti-Hezbollah parties in Lebanon, as well as fears Israel could escalate its strikes if the group remains armed.

Iran appointed 68-year-old Larijani to head the Supreme National Security Council, which is responsible for laying out Iran's defence and security strategy. Its decisions must be approved by the country's supreme leader, Ayatollah Ali Khamenei.

The appointment comes after a 12-day war with Israel, which began the conflict with an unprecedented attack on Iran in mid-June striking military, nuclear and residential sites.