US warns Iran of 'serious consequences' if it attacks Israel after IDF's invasion of Lebanon and reveals 'thousands' more troops will be sent to Middle East amid fears America will be drawn into full-scale regional war

Iran will face 'serious consequences' if it attacks Israel, the US has warned, as thousands of American troops have been sent to the region amid fears that fighting between Israel and Hezbollah in Lebanon could escalate into all-out regional war.

US fighter jet squadrons are being deployed, including F-15E and F-16s - jets which played a significant role in shooting down Iranian drones when Tehran launched a missile and drone attack on Israel back in April.

F-22 jets and A-10 warplanes are also being sent, while the USS Abraham Lincoln aircraft carrier is already positioned in the Gulf of Oman, with the USS Harry S Truman on its way as part of a scheduled deployment.

A 'few thousand' more American troops are also being moved to the region, the Pentagon said last night, to bolster security for the 40,000 already based across bases in Iraq, Syria and elsewhere.

The Biden administration is hoping to avoid the situation spiralling into a broader war that could potentially drag in US forces, and has urged Israel to keep its incursion limited in scope. 

Overnight, Israel said its forces engaged in 'limited, localised, and targeted ground raids' against Hezbollah in southern Lebanon villages that posed 'an immediate threat to Israeli communities in northern Israel'.

Defense Secretary Lloyd Austin, in a call with his Israeli counterpart Yoav Gallant on Monday night, said the US 'supports Israel's right to defend itself.'

'We agreed on the necessity of dismantling attack infrastructure along the border to ensure that Lebanese Hizballah cannot conduct October 7-style attacks on Israel's northern communities,' he wrote on X.

He added that 'I reiterated the serious consequences for Iran in the event Iran chooses to launch a direct military attack against Israel,' Austin said.

On Sunday, Austin warned that 'should Iran, its partners or its proxies use this moment to target American personnel or interests in the region, the United States will take every necessary measure to defend our people.'

Ahead of the incursion last night, Israeli Prime Minister Benjamin Netanyahu issued his own warning to Iran, which backs Hezbollah and Hamas. 

'There is nowhere in the Middle East Israel cannot reach,' Netanyahu said, just days after an airstrike south of Beirut killed Hassan Nasrallah, the long-time leader of the Hezbollah.

The group's acting leader, Naim Kassem, said his fighters were 'ready for war' and  prepared to fight on for a long time if necessary. 

Israel has also assassinated several of the group's top commanders in recent days. Kassem said the group's fighters and slain commanders have already been replaced.

It is unclear what response Iran may have to the attack on its proxy, with official in Tehran said to be divided on what next steps to take.

A repeat of April's massive missile and drone barrage on Israel is one possibility, but analysts have suggested that Iran will not launch such an attack unless they expect the probability of success to be higher than before.

There are also fears that Iran and its proxies could carry out terror attacks on Israel, or renew strikes by against US military bases and personnel in the Middle East. 

It comes after the Biden administration advised its ally Israel against launching a major ground invasion in Lebanon, calling instead for a more targeted incursion, according to US officials.

But more hardline elements of Israel's government, including National Security Minister Itamar Ben Gvir, this morning called for a wider operation to 'crush the terrorist organisation'. 

Israeli officials were reportedly left frustrated with the US and IDF after plans for the 'limited' ground invasion were leaked hours ahead of the move against Hezbollah.

When questioned by reporters on the operation, President Biden appeared to confirm the claims, saying: 'I'm more aware than you might know.'

Asked whether he was comfortable with the operational plans, he said: 'I'm comfortable with them stopping. We should have a cease fire now.'

On Friday, Netanyahu made a defiant speech to the UN, ignoring calls for a ceasefire from the US, Britain and others, and instead stating that Israel would push ahead with its objectives and defend itself against Iran.

'If you strike us, we will strike you. There is no place - there is no place in Iran - that the long arm of Israel cannot reach. And that is true of the entire Middle East,' Netanyahu said.

Hezbollah has promised to keep firing rockets into Israel until there is a ceasefire in Gaza. 

Israel and Iran-backed group have traded fire across the Lebanon border almost daily since October 8, the day after Hamas sent fighters into Israel and sparked the war.

Israeli ground and air attacks on the strip have seen over 40,000 Palestinians killed in the months since, according to the Gaza health ministry.

It's been almost a year since some 250 people were abducted from Israel, and friends and family are worried about their loved ones as attention turns away from hostages and north toward Lebanon.