The US has vowed that there will be “severe consequences” for Iran after it launched a ballistic missile attack on Israel in a “significant escalation” of the conflict in the Middle East.

Around 200 missiles rained down on Jerusalem and Tel Aviv, according to a senior Israeli official, who said: “Iran has declared war directly on the State of Israel.”

Social media footage showed missiles and explosions lighting up the night sky, arriving thicker and faster than in a previous Iranian strike on Israel in April.

Iran said the attack used hypersonic missiles for the first time and was in revenge for the assassination of Hassan Nasrallah, the leader of the Iranian-backed Lebanese terror group Hezbollah.

Jake Sullivan, the White House national security adviser, said: “We have made clear that there will be consequences, severe consequences, for this attack, and we will work with Israel to make that the case.”

The Iranian Revolutionary Guard Corps (IRGC) responded by saying it would launch a “crushing” response if Israel retaliated.

Western leaders urged all sides to pull back from the brink. Sir Keir Starmer spoke to Benjamin Netanyahu, the Israeli prime minister, as well as the King of Jordan to condemn the Iranian attacks and call for de-escalation across the region.

A gas platform was reportedly hit in Ashkelon as air raid sirens went off across Israel. Most of the missiles appeared to have been intercepted by Israel’s Iron Dome defence system and the Israeli Defense Forces said no casualties had been reported.

In the Jaffa area of Tel Aviv, eight people were killed in a terrorist shooting that was launched simultaneously with the missile strike.

Rear Admiral Daniel Hagari, a spokesman for the IDF, said: “We will defend the citizens of the State of Israel. This attack will have consequences. We have plans, and we will operate at the place and time we decide.”

The IRGC said the missile attack came after a “period of restraint” following an “attack on the sovereignty” of Iran, a reference to the killing of Ismail Haniyeh, the Hamas leader, in Tehran in July. “If the Zionist regime responds to Iran’s operations, it will face crushing attacks,” an IRGC spokesman said.

Ayatollah Ali Khamenei, Iran’s supreme leader, said in a statement: “With God’s help, the blows of the uprising front will become stronger and more painful on the worn and rotting body of the Zionist regime.”

Mr Khamenei remains in a secure location, a senior Iranian official said, where he has been since the assassination of Nasrallah last week.

Masoud Pezeshkian, the Iranian president, said: “Netanyahu should understand that Iran is not warlike, but it will stand firmly against any threat.

“This is only a glimpse of our capabilities. Do not engage in conflict with Iran.”

But the White House made clear that Iran must pay a price for its latest act of aggression.

Mr Sullivan said: “Based on what we know at this point, this attack appears to have been defeated and ineffective. We are proud of the actions that we’ve taken alongside Israel to protect and defend Israel.

“Obviously, this is a significant escalation by Iran, a significant event, and it is equally significant that we were able to step up with Israel.”

He said Washington would discuss “next steps” with Israel.

The missile attack came just hours after Israel launched a ground invasion of southern Lebanon aimed at pushing back Hezbollah from the border and creating a buffer zone between the two countries.

As the world waits to see how Israel will respond to the missile attack, there was pressure from Israeli hawks to take out Iran’s nuclear enrichment sites, including the Natanz uranium enrichment facility 200 miles from Tehran where Iran is close to producing bomb-grade uranium.

Democratic Congressman Jared Moskowitz, seen as a moderate, said: “Iran has made a mistake, it has put its nuclear facilities on the board as fair game.” 

Mr Netanyahu said in a speech to the UN earlier this week that the “long arm of Israel” could reach anywhere in the Middle East.

After the April attack, Israel launched a somewhat muted response, striking Isfahan, a city surrounded by nuclear facilities.

According to the Wall Street Journal, Israel warned Iran before the attack it would respond to any strike on its territory with hits on Tehran’s nuclear or oil facilities.

President Joe Biden directed the US armed forces to help Israel shoot down some of the missiles in the attack on Tuesday, the White House said.

Lloyd J Austin, the US defence secretary, told Yoav Gallant, the Israeli defence secretary, that America stood ready to defend Israel from further Iranian threats.

A Pentagon official said Mr Austin “made it clear that the United States is well postured to defend US personnel, allies and partners in the face of threats from Iran and Iran-backed terrorist organisations”.

Footage showed Iranian missiles falling in the vicinity of Nevatim air base, which is home to Israel’s fleet of F-35 fighter jets. Dozens of flashes of orange light could be seen hitting the ground in videos widely circulated on social media in the wake of the attack. 

The Iron Dome system is set up only to intercept incoming targets that are headed towards populated areas. If the system determines that a missile is going to land in an open location, the munition is allowed to hit the ground in order to conserve expensive interceptor rockets.

Mr Sullivan said he was not aware of “any damage to aircraft or strategic military assets in Israel”.

US naval destroyers deployed in the eastern Mediterranean Sea joined Israeli attempts to head off the attack.

USS Bulkeley and the USS Cole both fired to intercept Iranian missiles, said General Pat Ryder, the Pentagon’s spokesman. The vessels were in the area as part of a bolstered presence aimed at monitoring tensions in the Middle East.

Meanwhile, presidential candidate Donald Trump said Mr Biden and Kamala Harris, the vice-president, were leading the world “to the brink of World War III” because of their weak leadership.

He said the world “is on fire and spiralling out of control” and that “we have no leadership, no one running the country”.

A meeting of the emergency Cobra committee was held in Whitehall, after David Lammy, the Foreign Secretary, spoke to Ali Bagheri, his Iranian counterpart, to urge restraint.

The Foreign Office is not commenting on potential British involvement in helping Israel defend itself against Iranian missiles.

Attack began while Starmer was on phone

Downing Street said the missile attack began while Sir Keir was on the phone to Mr Netanyahu.

A spokesman said: “The Prime Minister spoke to Israel’s Prime Minister Benjamin Netanyahu this afternoon, and they discussed the escalating situation across the Middle East.

“The Prime Minister condemned Iran’s attack on Israel today in the strongest terms, which began during the leaders’ conversation, and expressed the UK’s steadfast commitment to Israeli security and the protection of civilians.

“During the call, the Prime Minister also underlined the importance of a ceasefire in Lebanon to allow space for a political solution in line with UNSC resolution 1701. The Prime Minister also raised the situation in Gaza and the importance of a ceasefire and action to bring home the hostages.”

Sir Keir also spoke to King Abdullah of Jordan about the “urgent need for a ceasefire” in both Lebanon and Gaza.

“The Prime Minister said he will work alongside partners and do everything possible to push for de-escalation and push for a diplomatic solution.”

Earlier on Tuesday, Britons in Lebanon were warned that the UK could not guarantee getting them out quickly if the “febrile and fragile” situation deteriorated.

It is still hoped that a UK-chartered flight will leave Beirut on Wednesday to take British citizens out of the country. Britain is also seeking to buy dozens of seats on commercial airlines to help people leave.

Mr Lammy urged British nationals in Lebanon to leave, warning that the airport in Beirut could be closed if fighting continued.

Speaking to broadcasters at the Foreign Office, Mr Lammy said: “I have warned and cautioned now for months that we have seen, in previous crises between Israel and Lebanon, the airport close, and we cannot guarantee that we will be able to get people out in speedy fashion.

“And of course, this is now turning into a very, very concerning situation on the ground.”