Theresa May will strengthen the UK's digital defences through a £15m online security pact with Commonwealth allies amid warnings over the growing threat of cyber warfare from Russia.
Leaders from the 53-nation bloc are expected to sign the world's largest cyber declaration, pledging to join forces to combat criminals and hostile actors engaged in potentially devastating cyber attacks, and to support smaller nations to raise their security standards by 2020.
It comes after UK and US intelligence agencies issued an unprecedented joint alert on the threat of "malicious cyber activity" by Russian state-sponsored hackers, as tensions with Moscow deepen over airstrikes in Syria.
Speaking ahead of an official meeting with Commonwealth leaders, Ms May said: “Cyber security affects us all, as online crime does not respect international borders.
“I have called on Commonwealth leaders to take action and to work collectively to tackle this threat. Our package of funding will enable members to review their cyber security capability, and deliver the stability and resilience that we all need to stay safe online and grow our digital economies.
“The Commonwealth plays a pivotal role in shaping the future for many of its members.
"We have put security on the agenda for the first time so we can work together and build a safer future both for Britain, and for the 2.4 billion people around the world who live in the Commonwealth.”
The prime minister will hold high level-talks on Wednesday with Australian prime minister Malcolm Turnbull, New Zealand's Jacinda Ardern and Canada's Justin Trudeau - the other members of the so-called "Five Eyes" group along with the US.
Russian hackers have been mounting attacks on millions of devices around the world to spy, harvest data and build networks, UK and US intelligence agencies warned on Monday, with a joint alert on the threat of "malicious cyber activity" backed by the Kremlin.
The National Cyber Security Centre (NCSC), along with the FBI and the US Department of Homeland Security, issued a statement to say Kremlin actions threaten "our respective safety, security and economic well-being".
Some efforts are aimed squarely at the UK government, and vital services such as the NHS, which was struck by a devastating ransomware attack last year.
Foreign Secretary Boris Johnson warned that the UK must "take every possible precaution" to defend itself from Russia following speculation the Kremlin was planning to retaliate with cyber warfare over airstrikes on Syria, its ally.
The UK joined a US-led coalition to mount an attack on a military facility near Homs, after intelligence suggested chemical weapons were being kept on site.
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