Israeli Prime Minister Benjamin Netanyahu has threatened consequences in the event of an Iranian attack on his country.
"Iran has been acting against us for years, both directly and through its proxies; that is why Israel is taking action against Iran and its proxies, defensively and offensively," Netanyahu said at the start of a meeting of the Israeli security cabinet on Thursday evening, his office announced.
"We will know how to defend ourselves and we will act according to the simple principle: Whoever harms us or plans to harm us, we will harm them," Netanyahu said.
The Israeli government and its ally the US are concerned that Iran is preparing for an imminent attack, the news portal Axios quoted American and Israeli officials as saying.
Iran had announced retaliation following a suspected Israeli airstrike on an Iranian embassy building in Syria's capital Damascus that left several people dead.
Two brigadier generals and five other members of Iran's powerful Islamic Revolutionary Guard Corps (IRGC) were killed in the attack on Monday. The Revolutionary Guards are Iran's elite military force and are considered more powerful than the conventional armed forces.
The Iranian threats against Israel were also discussed in a telephone conversation between US President Joe Biden and Netanyahu on Thursday. According to the White House, Biden made it clear that the US supports Israel in the face of these threats.
US support for Israel to defend itself against a range of threats remains "unwavering," said National Security Council Communications Director John Kirby.
Israel had told its ally that if Iran launched an attack on Israel from its soil in retaliation for the deadly attack in Syria, it would face a strong response from Israel and this would take the current conflict to another level, the Axios news portal quoted Israeli officials as saying.