The UK has been urged to pump money into an Israeli-style "Iron Dome" system as a matter of urgency as worries over British defence capabilities continue to mount.

Former US national security adviser General HR McMaster called on Britain to develop its own version of the high-tech missile defence system - as well as bump up its military spending to four per cent of UK GDP - higher than the two per cent Nato target.

Speaking to LBC, Gen McMaster said a spending hike would pay dividends, claiming "it’s a heck of a lot cheaper to prevent a war than have a fight".

The ex-adviser, when asked whether the UK should establish its own version of the Iron Dome, said: "I think that every country is going to have to develop these kinds of defences and long-range missiles."

He continued: "I think it's quite urgent for the United Kingdom, the United States, for all nations to invest more in defence.

"What we've seen is we have a huge gap in our defence-industrial base, and in the capacity of all of our services, as well as suffering from a bow wave of deferred modernisation.

"So I go back to what George Marshall said about the lead into the Second World War... He said: 'When you have the time, you don’t have the money. And when you have the money, you don’t have the time.'

"So it’s important, I think, to spend now on defence, recognising that it’s a heck of a lot cheaper to prevent a war than to have to fight."

MORE ON BRITISH DEFENCE WOES:

Britain's army could be 'unable to fight abroad,' warns UK's top general as he outlines major risk
Vladimir Putin has Britain in his crosshairs as expert warns UK army has 'never been so weak'
Israeli ambassador to UK - ‘No one can really expect Israel to do nothing'

When asked by Andrew Marr if he thought the UK should raise defence spending to three per cent, Gen McMaster said: "How about four per cent? That would be a historic low relative to Cold War levels."

Gen McMaster's calls echo those from inside the UK to implement its own Iron Dome - led by leader of the Commons Penny Mordaunt and ex-armed forces minister James Heappey.

And the chief of the defence staff - the head of Britain's armed forces - Admiral Sir Tony Radakin, has said a "live conversation" was ongoing over implementing such a system, which he declared "will be needed in the future".

Also speaking to LBC, Radakin said: "We’ve got certain capabilities at the moment that help to protect the UK and to help our forces when they’re stationed abroad.

"We don’t have the same kind of system that Israel has, but we don’t live in the same type of neighbourhood that Israel lives in. So, that’s why it’s very different - and we also are part of this big alliance.

"But when you look at the threats that are out there, far more longer-range missiles, far more longer-range one-way attack drones, much easier ways of delivering those - that’s why we’ve got various initiatives, both for ourselves as the UK but also with our European allies, about how we might better defend ourselves in the future, conscious that those threats are probably going to increase."

Israel's Iron Dome, an automated defensive missile system, works by identifying and intercepting airborne rockets and artillery shells mid-air before they can hit civilian targets in cities and other population centres.

The embattled country is the only state which uses such a system - and it proved decisive last month when Israel faced down a barrage of Iranian drone and missile attacks, with dramatic footage circulating online of explosions punctuating the night sky as the Iron Dome countered the attacks.

But the system is markedly expensive - each missile can cost up to $50,000 (£40,000), and the US has invested several billion dollars in propping it up; implementing an Iron Dome in the UK would likely carve out a significant chunk of Britain's defence budget, which stands at an estimated £55billion for 2024/25.