Ukrainian forces are restraining one of Russia's most powerful offensives since the start of Moscow's full-scale invasion on its smaller neighbour, the top commander of Kyiv's forces said on Saturday.

       Russian troops advanced in September at their fastest rate since March 2022, the month after President Vladimir Putin ordered the invasion, according to open-source data. Ukraine in August took part of Russia's Kursk region.

       "The Armed Forces of Ukraine are holding back one of the most powerful Russian offensives from launching a full-scale invasion," General Oleksandr Syrskyi wrote on the Telegram messaging app.

       After failing to capture the capital Kyiv early in the war and win a decisive victory, Putin scaled back his war ambitions to taking the Donbas industrial heartland in Ukraine's east, which covers the Luhansk and Donetsk regions.

       Donbas has since become the war's main theatre, where some of biggest battles in Europe for generations have taken place and where thousands of troops on each side have died.

       On Saturday, Moscow said it has taken two more settlements along the Donbas frontline. In the week of Oct. 20-27 alone, Russia captured nearly 200 square km (80 square miles) of Ukrainian territory, according to the Russian media group Agentstvo, which analysed Ukrainian open-source maps.

       The war is entering what Russian analysts say is its most dangerous phase as Moscow's forces advance, North Korea sends troops to Russia and the West ponders how the conflict will end.

       Ukraine's President Volodymyr Zelenskiy has been travelling the world lobbying NATO countries to allow Kyiv the use of the long-range missiles they have provided to strike targets deep inside Russia.

       Ukraine is bracing for what could be the toughest winter of the war after long-range Russian airstrikes destroyed what officials say is about half of its power generating capacity. REUTERS