IRAN’S most heavily fortified nuclear base must be destroyed as part of operation Rising Lion, Israel’s ambassador to the US said.

The infamous Fordow Fuel Enrichment Plant is the paragon of the Ayatollah’s nuclear programme and a symbol of the regime’s technological capabilities.

Located just 100 miles south of the capital Tehran, Fordow is one of two nuclear enrichment sites in the country.

The other, which is based in Natanz, was reportedly partially destroyed as part of Israel’s operation Rising Lion.

The precise missile blitz aimed at crippling Tehran’s nuclear weapon developments come as Iran and Israel teeter on the brink of all out war.

Both sides continue to exchange deadly missile strikes, following Tel Aviv accusing Tehran of trying to develop a nuclear bomb last week.

Despite Israeli airstrikes successfully killing 14 Iranian nuclear scientists, wiping out top military brass and destroying key buildings – Fordow remains unscathed.

Buried deep inside the mountains with key facilities embedded up to 100 metres underground, Fordow remains to be a challenging target.

Its key purpose is pumping out enriched uranium – critical to developing nuclear warheads.

Centrifuges hidden deep down in the bunker are reportedly enriching uranium at up to 60 per cent, just below the crucial 90 per cent needed to create a nuclear weapon.

Explaining the goals of operation Red Lion, Israeli ambassador to the US Yechiel Leiter said that “the entire operation… really has to be completed with the elimination of Fordow.”

The key bunker has even been branded as the “the be-all and end-all of Iran’s nuclear operation”.

Former Middle East diplomat Brett McGurk said: “If you don’t get Fordow, you haven’t eliminated their ability to produce weapons-grade material.”

Protected within an Islamic Revolutionary Guards Corp base, the mountainous site is heavily surveilled.

Guard towers stand 25 metres apart, primed air defences ring the perimeter, and a support headquarters is stationed nearby.

Satellite imagery shows two massive rings of steel fencing around the site – each with heavily armed checkpoints along the entrance road.

Up to three tunnel entrances can be seen in the centre – each one heavily guarded.

Fordow is protected against a range of conventional bomb attacks and could potentially even fend off hugely powerful so-called “bunker buster” bombs.

The world’s largest bomb is the Massive Ordnance Penetrator, delivered by B-2 bombers and exclusively made by the US.

These may be enough to reach the base’s deepest points, according to reports.

But Washington has made its stance clear on the unilateral operation Red Lion, saying it would not directly get involved in Israel‘s conflict with Iran.

The Ayatollah’s pariah state has been enriching uranium at Fordow since September 2011.

The site’s existence was revealed two years before that, when British, French and US intelligence reports detailed a secret facility “inconsistent with a peaceful [nuclear] programme.”

The Islamic Republic has long denied seeking to develop nuclear weapons.

But last week, the International Atomic Energy Agency (IAEA) reported that Iran had been producing 60 per cent purity uranium.

This uranium would be capable of being further enriched to the 90 per cent weapons grade benchmark.

Israel said this was proof that Iran was building a nuclear bomb -before launching their sophisticated missile blitz.

On Monday, Pakistan warned they would nuke Israel, according to a senior Iranian general amid the deadly missile salvos across the Middle East.

Strikes have been raining down across both countries for the last four days – with the US embassy in Tel Aviv now being damaged.

Tension is now skyrocketing as the conflict threatens to spiral into a wider regional war with Pakistan also calling for the Islamic world to back Iran.

America could also be pulled into the conflict, with Donald Trump warning the “full strength and might” of the US military would be used if American assets were targeted.

Damage to the embassy was done during a third night of fierce missile exchange between Iran and Israel, with Benjamin Netanyahu claiming “regime change” in Tehran is imminent.

Mike Huckabee, the US ambassador in Israel, said the embassy in Tel Aviv was damaged “from concussions of Iranian missile hits” near the building but that no personnel were injured.

Benjamin Netanyahu said just before his latest blitz that Iran is now “very weak” as he warned of an impending “regime change” in Tehran.