A UK programme has been secretly helping Ukraine defend against Russian cyber attacks, it can now be revealed.
Details of the £6m package had not been made public before to protect operational security, officials say.
Ukraine saw unprecedented attacks from a range of Russian intelligence services, according to those involved in the programme.
But Ukrainian defences – supported by its allies – helped it withstand many of the attempts to take down systems.
Russia has repeatedly dismissed claims it has carried out cyber attacks.