Maj. Gen. Yahya Rahim Safavi, the top military adviser to Iran's Supreme Leader Ayatollah Ali Khamenei, said none of the Israeli embassies are safe now, which is why it has closed down 28 embassies this week.
The former commander of the Islamic Revolutionary Guard Corps (IRGC) said the April 1 missile attack on a building serving as the Iranian Embassy's consular affairs wing in Damascus, Syria, "violated international laws" as the slain Iranian military officials were there "at the invitation" of Syria.
At least 13 people were killed in the attack, including seven IRGC officers, which Iranian authorities blamed on Israel.
Among those killed were General Mohammad Reza Zahedi, a senior commander of the IRGC's Quds Force in Syria and Lebanon, and his deputy General Hadi Haj Rahimi.
Safavi said Iran's Supreme Leader Khamenei has vowed a "regretful slap" on Israel and that the "resistance front" is ready for retaliation.
"We will have to wait and see what happens," the senior military official said, confirming speculation that Iran is weighing its options to avenge the Damascus attack.
According to media reports, at least 28 Israeli diplomatic missions in the West Asia region have been closed in recent days amid anticipation for any Iranian retaliatory action.
In a statement on Tuesday, a day after the attack, Khamenei said Israel "will be punished at the hands of our brave men," adding that the Iranian military will make Israel "regret the crime."
Iranian Foreign Minister Hossein Amir-Abdollahian, who embarked on a regional tour on Sunday, met senior Yemeni Houthi official Mohammad Abdul Salam in the Omani capital, Muscat.
He said the attack on the Iranian consulate building in Damascus was carried out with US-made aircraft and missiles, vowing to "hold the criminal aggressors accountable."
Amir-Abdollahian is slated to visit Damascus as well, according to reports.
It comes amid heightened tensions in the region sparked by Israel’s deadly offensive on the Gaza Strip and related developments, including attacks on Israeli and US interests in the region by Iran-allied groups in Iraq and Yemen.