Russian forces are advancing in Ukraine at the fastest rate since the early days of the 2022 invasion, taking an area half the size of London over the past month, analysts and war bloggers say.
The war is entering what some Russian and Western officials say could be its most dangerous phase after Moscow's forces made some of their biggest territorial gains and the United States allowed Kyiv to strike back with US missiles.
"Russia has set new weekly and monthly records for the size of the occupied territory in Ukraine," independent Russian news group Agentstvo said in a report.
The Russian army captured almost 235 square kilometres (sq km) in Ukraine over the past week, a weekly record for 2024, it said.
Russian forces had taken 600 sq km in November, it added, citing data from DeepState, a group with close links to the Ukrainian army that studies combat footage and provides frontline maps.
Russia began advancing faster in eastern Ukraine in July just as Ukrainian forces carved out a sliver of its western region of Kursk. Since then, the Russian advance has accelerated, according to open-source maps.
Russia currently controls 18 per cent of Ukraine including all of Crimea, just over 80 per cent of Donbas, which comprises Luhansk and Donetsk, and more than 70 per cent of the Zaporizhzhia and Kherson regions, as well as just under 3 per cent of the Kharkiv region, according to open source maps.
Neither side publishes accurate data on their own losses though Western intelligence estimates casualties to number hundreds of thousands killed or injured, while swathes of eastern and southern Ukraine have turned into wastelands.
War's largest drone strike
The major push by Russia along front lines in Ukraine's east has also coincided with intensified nightly drone attacks on Ukrainian cities.
Russian forces staged their largest ever drone attack on Ukraine overnight, cutting power to much of the western region of Ternopil and damaging residential buildings in Kyiv region, Ukrainian officials said on Tuesday.
Of 188 drones used overnight, Ukraine shot down 76 and lost track of 96, likely due to active electronic warfare, the air force said. Five drones headed towards Belarus.
"The enemy launched a record number of Shahed attack UAVs and unidentified drones ...," it said. Russia uses cheaply-produced "suicide" drones and low-cost "decoy" drones, which tie up Ukrainian air defences.
"Unfortunately, there were hits to critical infrastructure facilities, and private and apartment buildings were damaged in several regions due to the massive drone attack," an air force statement said, adding that no casualties had been reported.
Zelenskyy calls for air-defence boost
The Washington-based Institute for the Study of War said in a report that "Russian forces' advances in southeastern Ukraine are largely the result of the discovery and tactical exploitation of vulnerabilities in Ukraine's lines".
The report also said that Russian forces have recently been advancing "at a significantly quicker rate than they did in the entirety of 2023".
President Vladimir Putin has repeatedly said that Russian forces are advancing much more effectively — and that Russia will achieve all its war aims in Ukraine.
Putin's foreign intelligence chief Sergei Naryshkin said on Tuesday that Russia was categorically opposed to a "freezing of the conflict" because Moscow needed a "solid and long-term peace".
Ukrainian President Volodymyr Zelenskyy has repeatedly said peace cannot be established until all Russian forces are expelled and all territory captured by Moscow, including Crimea, is returned.
But outnumbered by Russian troops, the Ukrainian military is struggling to recruit soldiers and provide equipment to new units.
Zelenskyy has said he believed Putin's main objectives were to occupy the entire Donbas, spanning the regions of Donetsk and Luhansk, and oust Ukrainian troops from the Kursk region, parts of which they have controlled since August.
The president recently called on Ukraine's Western partners to concentrate their efforts on helping to improve the nation's air defence capabilities, in response to Russia's drone and missile strikes.
"The world has air defence systems capable of defending against this kind of threat too," he said. "This is what we all have to focus on."
