Israel braces for Iranian attack after US warning

Israel said Tuesday it was ready to counter any attack from Iran as a US official warned of an imminent missile strike, after Israeli raids against Hezbollah in Lebanon sent tensions soaring.

The Israeli ground offensive across the country's northern border came despite growing calls for de-escalation after a week of air strikes that killed hundreds in Lebanon, including Hassan Nasrallah, the powerful leader of Hezbollah.

A senior White House official told AFP that "the United States has indications that Iran is preparing to imminently launch a ballistic missile attack against Israel".

The Israeli military said it had not detected any "aerial threat" from Iran "for now" but stood ready to "defend and attack".

Defence Minister Yoav Gallant discussed the "imminent" Iran threat with Pentagon chief Lloyd Austin, a statement from his office said.

While Iran-backed groups like Hezbollah had already been drawn into the Gaza war, sparked by Palestinian group Hamas's October 7 attack on Israel, Tehran has largely refrained from direct attacks on its regional foe.

Early Tuesday, the Israeli military said troops had started "targeted ground raids" in south Lebanon, across Israel's northern border, though officials have provided few details of the scale of the operation or its timeframe.

The UN peacekeeping mission in Lebanon said the Israeli offensive did not amount to a "ground incursion" and Hezbollah denied any troops had crossed the border.

A Lebanese army source told AFP the force had "not observed any penetration by Israeli enemy forces".

There was no way to immediately verify the claims, which came as Israel struck south Beirut, Damascus and Gaza, despite international calls for restraint to avoid a regional conflagration.