Air Chief Marshal Sir Richard Knighton said the UK must catch up with European allies to counter the growing Russian threat. He warned that Moscow’s appetite for risk has grown, citing sabotage and cyber attacks. Britain now plans to increase military spending to 3 per cent of GDP by 2030.

Sir Richard Knighton promises further action to counter Moscow's submarines in the north Atlantic

The UK is lagging behind other European countries in understanding the threat posed by Russia, the head of the British military has warned, as he promised further action to counter Moscow's submarines in the north Atlantic.

Air Chief Marshal Sir Richard Knighton, chief of the defence staff, said that Britain needed to "catch up with our European allies", including those geographically closer to Russia who felt the proximity of its aggression and the war in Ukraine more acutely.

"We're talking about targeted assassinations, we're talking about sabotage, we're talking about cyber attacks. These are very real, real things [by] the Russian state we have proof of in Europe and to some extent in the UK," he told the FT in a rare interview ahead of Remembrance Sunday.

Knighton added that Moscow's "appetite" for risk "has quite clearly grown" and that the term "hybrid activity" no longer did justice to the gravity of its actions.

"This is the most dangerous period I've known in my adult life . . . That threat -- principally from Russia, but more broadly globally -- is rising," he said.

The British state must explain that to the public "particularly at a time when the government is asking society to spend more on defence", he added, referring to chancellor John Healey's vow in last month's Budget that Britain will increase military expenditure to 3 per cent of GDP by 2030. Analysts forecast the pledge will mean spending an extra £11bn a year on the armed forces.

His comments come on the eve of a naval pact aimed at bolstering defence of the north Atlantic, Arctic and Baltic regions.

The Joint Expeditionary Force -- a UK-spearheaded grouping that also includes the Netherlands, the Baltic states and Scandinavian countries -- will move "beyond memorandums of understanding and exchanges and meetings into really practical measures of how our navies and our air forces and our armies as well will work together".

"One of the things that's imperative is that we are able to hold back [Russian] submarines so that they are not able to target or to threaten shipping in wartime," Knighton said.

The so-called High North, which encompasses parts of the north Atlantic and the Arctic, has become increasingly vital to western economies and Nato security, partly owing to climate change and the increasing navigability of previously ice-covered areas..

Europeans' stronger presence there seeks to answer Donald Trump's call for them to shoulder more responsibility for their own defence and to bolster US security, given that vital subsea data cables traverse the region.

"By making that secure, we're also keeping the east coast of the US secure," Knighton said.

While Trump's position has weakened in the wake of the Republican rout in the US midterms, Knighton stressed that Washington's "tilt" away from Europe towards the Indo-Pacific long predated the president and had been going on "for 15 years or more".

Regardless of who comes next in the White House, he said: "We definitely need to, as Europe, step up in re-equipping ourselves and readying ourselves so that we can deter our adversary."

The agreement between the Joint Expeditionary Force is expected to be signed aboard the Royal Navy aircraft carrier HMS Prince of Wales on Tuesday, ahead of the Atlantic Future Forum conference on the warship.

Norway's purchase of British Type 26 anti-submarine warfare frigates last year, a £10bn deal, "is a really solid sign of [the partners' new] interoperability and ability to work together for the greater good of Nato," Knighton said.

Last month the head of the British Army issued a rallying cry to ready his soldiers for the prospect of war and warned them that political leaders would "very soon" embark on a "frank conversation" with citizens about how they needed to prepare for conflict.

Knighton reiterated that message, saying: "The stronger we are, the more likely we are to be able to deter Russia from testing us."