Ali Shamkhani, the secretary of the country's Supreme National Security Council, made the comment at the funeral for Mohsen Fakhrizadeh.

"If necessary, we will step up these attacks," said Israeli Prime Minister Benjamin Netanyahu.

Israeli PM Benjamin Netanyahu told Russia that Israel would not seek to topple its ally, Syrian President Bashar al-Assad, but Moscow should encourage Iranian forces to quit Syria.

The comments by Ayatollah Ahmad Khatami followed a week of escalating tensions that threaten to spill over into a wider conflict between the two bitter enemies.

Benjamin Netanyahu said Israel could act against Iran itself, not just its allies in the Middle East.

Israel's prime minister said Sunday his country delivered "severe blows" to Iranian and Syrian forces and vowed to take further action against its adversaries.

Anti-aircraft fire downed an Israeli warplane returning from a bombing raid on Iran-backed positions in Syria.