Ukraine has accused Russia of planning a wide-ranging ground offensive for early in the new year, despite recent Russian military setbacks.
President Volodymyr Zelensky and senior officials have warned that Kyiv and its allies must guard against complacency.
The offensive could come in the eastern Donbas region, in the south, or even towards Kyiv, senior generals say.
Western analysts say Russia’s ability to conduct successful offensive ground operations is rapidly diminishing.
Britain’s most senior military officer Admiral Sir Tony Radakin said this week that the war would only get worse for Moscow, which he added was now facing a critical shortage of artillery munitions.
In a series of briefings to the media, Ukraine’s Defence Minister Oleksii Reznikov said evidence was mounting that Russia, which has suffered a series of battlefield losses, plans a broad new offensive.
He speculated this could occur in February when half of the 300,000 troops conscripted by Russia in October to support the Ukraine war would complete training.
“The second part of the mobilisation, 150,000 approximately… do a minimum of three months to prepare. It means they are trying to start the next wave of the offensive probably in February, like last year. That’s their plan,” Mr Reznikov told the Guardian.
“The Kremlin is trying to find new solutions [for] how to get the victory,” he added, stating that he expects Russia to further mobilise more citizens.
Moscow’s new offensive could happen as soon as January but more likely in the spring, the Economist reported on Thursday, saying the assessment came from President Zelensksy, General Valery Zaluzhny and General Oleksandr Syrskyi in recent interviews.
“The Russians are preparing some 200,000 fresh troops. I have no doubt they will have another go at Kyiv,” said General Zaluzhny, the head of Ukraine’s armed forces.
Russia is “100% being prepared”, he said, adding that Ukraine’s “very important strategic task…is to create reserves and prepare for the war, which may take place in February, at best in March, and at worst at the end of January”.
“It may start not in Donbas, but in the direction of Kyiv, in the direction of Belarus, I do not rule out the southern direction as well,” he said.
Both sides have ruled out a Christmas truce and there are currently no talks aimed at ending the conflict.
Military analysts say a winter deadlock could set in, even as fierce fighting continues, especially in the Donetsk region, where Russian forces are pushing to capture the town of Bakhmut.
Ukraine has significantly improved its air defences against Russian missiles with Western support, but is calling for more advanced weaponry.
On Thursday, western allies stepped up their support with additional funding and military training.
European Union leaders agreed to provide €18bn (£15.7bn) in financing to Ukraine next year and hit Moscow with a ninth package of sanctions.
In Washington, the US military announced it will expand training in Germany of Ukrainian military personnel. Starting in January, 500 troops a month will be trained, building on more than 15,000 Ukrainians trained by the US and its allies since April.
