Five more Type 26 frigates will be built for the Royal Navy, the Prime Minister has announced.
Defence manufacturer BAE Systems has been awarded a £4.2 billion contract to build the five warships, on top of the three already under construction.
The Type 26 is designed for anti-submarine warfare and high-intensity air defence and can be adapted to supplying humanitarian aid during a disaster relief effort.
The new ships will replace the Type 23 vessels currently in operation by the Royal Navy.
Watch: Virtual tour of future Type 26 as it’s being built.
Defence Secretary Ben Wallace said: "We are investing in our fleet to ensure our Royal Navy maintains its world-leading capability to protect and defend our nation at sea.
"This design has already been successfully exported to Australia and Canada, proving itself as a world-class maritime capability, securing thousands of UK jobs and strengthening alliances with our allies.
"Supporting thousands of high-skilled jobs in Scotland, and more across the wider UK supply chain, this contract will continue to boost our British shipbuilding industry, galvanising the very best of British engineering, manufacturing and design."
Responding to the announcement, shadow defence secretary John Healey MP tweeted: "We welcome the go ahead for this second batch of world-class Type 26 warships being built in Britain. We now expect the Defence Secretary to deliver them as the threats increase.
"But the Defence Secretary has already conceded that the Type 26 programme is delayed and over-budget, and since 2010 the Conservatives have cut one in five of the Navy’s surface ships.
"Ministers must now place the Navy's Fleet Solid Support ships contract with British shipyards, as Labour in government would do."
Watch: Russia has 'yet again' failed one of its main objectives, Wallace says.
The first of the new class of frigates – HMS Glasgow – is due to be delivered to the Royal Navy by the mid-2020s.
The contract will also secure more than 4,000 jobs across BAE Systems and the wider UK maritime supply chain.
BAE Systems Chief Executive Charles Woodburn said: "This contract secures a critical UK industry and allows us to build on our long history of shipbuilding on the Clyde as we continue to deliver cutting-edge equipment to the Royal Navy into the next decade.
"It underpins the ongoing investments we’re making in the skills, infrastructure and technologies needed to stay at the forefront of the maritime sector and to support the UK Government’s National Shipbuilding Strategy."
Meanwhile, Rishi Sunak declined to commit to boosting defence spending to 3% of GDP – a promise made by his predecessor Liz Truss, as he and the Chancellor look to balance the books.
He downplayed concerns by some in the Tory party that ditching the target could be seen as a weakness by Russian President Vladimir Putin.
Speaking to reporters travelling with him to Bali, Indonesia, for the G20 summit, he said: "We've got not just a current but a historic track record of being strong investors in defence and prioritising Nato.
"I think people can feel completely assured that we're investing in our defences.
"In terms of what does weaken Putin, I mean what he's going to see from me is unequivocal condemnation of his actions at the G20."
The Bali summit looks set to be dominated by the fallout from Russia's invasion of Ukraine and Mr Sunak is preparing to confront Russia’s representative with allies at the summit, which starts on Tuesday.
Mr Sunak said "countries should not invade their neighbours" as he condemned Russia's invasion.
Facing Russian Foreign Minister Sergei Lavrov in the plenary hall, the Prime Minister called on Moscow to "get out of Ukraine and end this barbaric war" as he blamed the conflict for worsening global economic challenges.