Kyiv is on alert for a possible large-scale Russian offensive in Ukraine's east in mid to late February.

Governor Serhiy Haidai of Ukraine's eastern region of Luhansk told local media on Monday that Russian forces are bringing ammunition to the frontlines. He also said the troops appear to be saving the use of ammunition and preparing to launch a large-scale offensive. The governor said he is expecting a massive Russian offensive on or after February 15.

In the eastern region of Donetsk, the Russian military is stepping up attacks to capture the city of Bakhmut, a Ukrainian stronghold.

The Institute for the Study of War, a US think tank, said, "Russian forces continue ground attacks northeast and south of Bakhmut but still have not encircled the settlement as of February 6."

The institute also said, "Ukrainian officials assess that Russian forces are preparing to launch a large-scale decisive offensive in eastern Ukraine in mid-to-late February."

Britain's defense ministry said the aim of Russia's troops is almost certainly to capture remaining Ukrainian-held parts of the Donetsk region.

But it said Russian forces have only managed to gain several hundred meters of territory per week, and that this is due to a lack of munitions and maneuver units.

The ministry said, "Russian leaders will likely continue to demand sweeping advances. It remains unlikely that Russia can build up the forces needed to substantially affect the outcome of the war within the coming weeks."