"We will restore Britain's war-fighting readiness as the central purpose of our armed forces," Starmer wrote in The Sun daily, including by ramping up weapons production capacity.

His government's Strategic Defence Review, due to be published Monday, will assess threats facing the UK, amid Russia's ongoing war in Ukraine and pressure from US President Donald Trump for NATO allies to bolster their own defences.

Starmer wrote that It will serve as "a blueprint for strength and security for decades to come".

Defence Secretary John Healey warned of "growing Russian aggression", including through "daily" cyberattacks on the UK's "defence system".

"We're in a world that is changing now... and it is a world of growing threats," Healey told the BBC on Sunday.

"It's growing Russian aggression. It's those daily cyberattacks, it's new nuclear risks, and it's increasing tension in other parts of the world as well."

The defence review will recommend "creating an 'always on' munitions production capacity in the UK" allowing the scaling up of weapons production if needed, according to the Ministry of Defence.

The document also urges the government to create conditions in industry to boost munition stockpiles.

In February, Starmer committed to hiking defence spending to 2.5 percent of GDP by 2027, up from its current 2.3 percent, and to further raise it to three percent by around 2029.

His Labour administration has said it would cut UK overseas aid to help fund the spending.

- New technologies -

On Saturday the government announced pound1.5 billion ($2 billion) for building "at least six munitions and energetics factories" as well as procuring 7,000 domestically built long-range weapons.

This investment -- which will see pound6 billion spent on munitions under the current parliament -- would create and support 1,800 jobs.

"We are strengthening the UK's industrial base to better deter our adversaries and make the UK secure at home and strong abroad," Healey said.

The Ministry of Defence also pledged pound1 billion for the creation of a "cyber command" to help on the battlefield.

The defence shake-up "means bringing together every capability we have, from drones, to artillery, to human instinct and intelligence, into one formidable, integrated fighting machine," Starmer said.

The review, led by former NATO secretary general George Robertson, warns that Britain is entering "a new era of threat" as drones and artificial intelligence transform modern warfare, The Guardian newspaper reported Saturday.

The document will describe the "immediate and pressing" danger posed by Russia, as well as focusing on China, Iran and North Korea.

Robertson has described the four countries as a "deadly quartet" which were "increasingly working together".