Israeli Prime Minister Benjamin Netanyahu hit out at Iran on Wednesday after President Hassan Rouhani accused Israel of supporting "terrorists" in Syria.
"Absurdity has no limits: Iran's terrorist regime that sends tentacles of terror across the region accuses Israel of terrorism," Netanyahu wrote on Twitter.
"If Rouhani is unaware of the terrorist and sabotage activities conducted daily by the Iranian Quds Force in Syria, Israel can provide him with an update," Netanyahu said, referring to the foreign arm of Iran's elite Revolutionary Guards.
Earlier Wednesday, during a summit in Ankara with Turkish President Recep Tayyip Erdogan and Russia's Vladimir Putin, Rouhani denounced "the daily support of the Zionist regime for terrorists in Syria", according to the website of the Iranian presidency.
Tehran is a key backer of Syrian President Bashar al-Assad's regime, but Israel does not want its arch-rival to entrench itself militarily next door.
In February Israel carried out major air raids in Syria, including against sites it described as Iranian targets.
Iran has also long supported Islamist group Hamas, which controls the Gaza Strip and has fought three wars with Israel since 2008.
Iranian supreme leader Ayatollah Ali Khamenei has written to Hamas chief Ismail Haniya pledging the Islamic republic's backing "in any form".
"It is a religious duty and an obligation as human beings ... and, God willing, we will act in accordance with this obligation, as in the past," he wrote.
Excerpts of the letter were published Wednesday on Khamenei's website after de facto Saudi leader Crown Prince Mohammed bin Salman said Israel has a "right" to a homeland, in a notable shift in the kingdom's position.
Saudi Arabia and Israel have no formal diplomatic relations, but behind the scenes their ties appear to have improved in recent years against what they see as a common Iranian threat.