LONDON (AP) -- The United Kingdom will build new nuclear-powered attack submarines and create an army ready to fight a war in Europe as part of a boost to military spending designed to send a message to Moscow -- and Washington.

Prime Minister Keir Starmer said Britain "cannot ignore the threat that Russia poses" as he pledged to undertake the most sweeping changes to Britain's defenses since the end of the Cold War more than three decades ago.

"We have to recognize the world has changed," Starmer told the BBC. "With greater instability than there has been for many, many years, and greater threats."

The government is to respond to a strategic defense review commissioned by Starmer and led by George Robertson, a former U.K. defense secretary and NATO secretary general. It's the first such review since 2021, and lands in a world transformed by Russia's full-scale invasion of Ukraine in 2022, and by the re-election of President Donald Trump last year.

The government says it will accept all 62 recommendations made in the review, aiming to help the U.K. confront growing threats on land, air sea and in cyberspace.

Defense Secretary John Healey said the changes would send "a message to Moscow, and transform the country's military following decades of retrenchment, though he said he does not expect the number of soldiers -- currently at a historic low -- to rise until the early 2030s.

Healey said plans for defense spending to hit 2.5% of national income by 2027 a year are "on track" and that there's "no doubt" it will hit 3% before 2034.

Starmer said the 3% goal is an "ambition," rather than a firm promise, and it's unclear where the cash-strapped Treasury will find the money. The government has already, contentiously, cut international aid spending to reach the 2.5% target.

Starmer said he wouldn't make a firm pledge until he knew "precisely where the money is coming from."

Even 3% falls short of what some leaders in NATO think is needed to deter Russia from future attacks on its neighbors. NATO chief Mark Rutte says leaders of the 32 member countries will debate a commitment to spend at least 3.5% of GDP on defense when they meet in the Netherlads this month.

Monday's announcements include building "up to 12" nuclear-powered, conventionally armed submarines under the AUKUS partnership with Australia and the United States. The government also says it will invest 15 billion in Britain's nuclear arsenal, which consists of missiles carried on a handful of submarines. Details of those plans are likely to be scarce.

The government will also increase conventional Britain's weapons stockpiles with up to 7,000 U.K.-built long-range weapons.

Starmer said rearming would create a "defense dividend" of well-paid jobs -- a contrast to the post-Cold War "peace dividend" that saw Western nations channel money away from defense into other areas.

Like other NATO members, the U.K. has been reassessing its defense spending since Russia's full-scale invasion of Ukraine in February 2022.

Healey said Russia is "attacking the U.K. daily," with 90,000 cyberattacks from state-linked sources directed at the U.K.'s defense over the last two years. A cyber command to counter such threats is expected to be set up as part of the review.

"This is a message to Moscow," Healey told the BBC.

It's also a message to Trump that Europe is heeding his demand for NATO members to spend more on their own defense.

European countries, led by the U.K. and France, have scrambled to coordinate their defense posture as Trump transforms American foreign policy, seemingly sidelining Europe as he looks to end the war in Ukraine. Trump has long questioned the value of NATO and complained that the U.S. provides security to European countries that don't pull their weight.

Robert Jenrick, justice spokesman for the main opposition Conservative Party, called on the government to be more ambitious and raise spending to 3% of national income by 2029.

"We think that 2034 is a long time to wait, given the gravity of the situation," he told Sky News.