Iran's president has vowed to defend Muslim countries against terrorism and Israel.

Speaking during a National Army Day parade on Sunday, Hassan Rouhani praised Iran's role in helping the Syrian and Iraqi governments roll back the Islamic State group, saying "if tomorrow your capitals face danger from terrorism or Zionism, the power that will give you a positive answer is the Islamic Republic of Iran."

In the speech, broadcast live by state TV, he emphasized that Iran's military power was for defensive and deterrent purposes, and should not be seen as a threat to its neighbors.

He appeared to be referring to Gulf Arab states, which have long viewed Iran as seeking to dominate the region. Saudi Arabia and Iran back opposite sides in the Syrian and Yemeni civil wars.