Russian forces are losing ground in Ukraine, allowing the country's own forces to reclaim certain key towns and positions just 20 miles from Kyiv, according to the UK's Ministry of Defence (MoD).
Ukrainian counter-attacks and issues with Russian supply lines are both allowing Ukraine to retake towns and defensive positions up to 21 miles (35km) east of Kyiv, the MoD said in an intelligence update.
After invading Ukraine a month ago, Russia has so far failed to capture a single major city.
Despite warnings that the war could see a quick Russian victory, its armoured columns are moving much slower than expected, with forces taking heavy casualties and running low on supplies.
In its intelligence update posted on Twitter on Friday (25 March), the MoD said: "Ukrainian counter-attacks, and Russian forces falling back on overextended supply lines, has allowed Ukraine to reoccupy towns and defensive positions up to 35 kilometres east of Kyiv.
"Ukrainian forces are likely to continue to attempt to push Russian forces back along the north-western axis from Kyiv towards Hostomel Airfield.
"In the south of Ukraine, Russian forces are still attempting to circumvent Mykolaiv as they look to drive west towards Odesa, with their progress being slowed by logistic issues and Ukrainian resistance."
Russian President Vladimir Putin has continued to claim the invasion is going to plan, but as well as unflinching opposition from Ukrainian forces, he is also said to face issues on home turf, with widespread protests in Russian cities and the risk of being ousted in a coup led by his own security services.
Watch: Kyiv mayor Vitali Klitschko says he cries 'every day' at destruction Putin has caused
Exiled Russian human rights activist, Vladimir Osechkin, said information from an unnamed source within Russia's Federal Security Service (FSB) suggested unrest is growing within the service.
Osechkin, who is wanted in Russia for his work exposing abuse in Russia's prisons, told The Times Putin is being blamed for Russia's inability to claim Ukraine, and senior figures are beginning to become disillusioned with the war over increasingly oppressive sanctions brought in by the West which are biting at the lives of ordinary Russians.