Tens of thousands of Russians are being sent to eastbound Ukraine arsenic portion of an violative planned aft 15 February, according to the Ukrainian politician of Luhansk region.
"We are seeing much and much reserves being deployed successful our direction," said Serhiy Haidai, who expected a three-pronged Russian advance.
Ukraine has warned repeatedly of an imminent offensive.
But determination is wide scepticism of important Russian success.
The UK's defence quality briefing said Russia's purpose was astir surely to seizure parts of Ukraine's eastbound Donetsk portion that were not already nether occupation.
But the UK said "it remains improbable that Russian tin physique up the forces needed to substantially impact the result of the warfare wrong the coming weeks".
Russian Defence Minister Sergei Shoigu said 7 Ukrainians towns had been "liberated" successful caller weeks and operations were progressing "with success" successful 2 more, Bakhmut and Vuhledar.
For six months, Russian mercenaries -now joined by regular troops - person tried to seizure Bakhmut, a tiny metropolis with a pre-war colonisation of 70,000.
Now a Ukrainian commander, Denis Yaroslavskiy, has said lone 2,000 civilians stay and Russian forces person captured parts of the eastbound and northbound of the metropolis and proceed to determination forward.
The caput of Russia's Wagner mercenary unit said this week that Ukrainian forces were not successful retreat anyplace successful the metropolis and fierce battles were taking spot for each street, location and stairwell.
Ukrainian President Volodymyr Zelensky said the subject was paying adjacent attraction to Russia's effort to encircle Bakhmut. "We are countering them," helium said connected Monday night.
He announced that leaders with subject acquisition were being appointed successful borderline and frontline regions, who could "prove themselves" against existent threats from Russia.
Ukrainian forces said connected Tuesday they had changeable down a Russian combat craft implicit Bakhmut, but determination was nary autarkic confirmation.
Russian forces person made small advancement successful Ukraine since their retreat from the large confederate metropolis of Kherson past November. Last period they captured the municipality of Soledar northbound of Bakhmut aft an aggravated battle.
Almost a twelvemonth into Russia's invasion, an estimated 300,000 Russian reserve troops person been recruited successful caller months successful an effort to interruption done Ukraine's beforehand lines successful the east. Capturing Bakhmut could alteration Russian forces to property connected towards the bigger cities of Kramatorsk and Slovyansk.
Mr Haidai said the Russians' two-month grooming play was coming to an extremity and Moscow would request astir 10 days to transportation them to the beforehand for a caller offensive. He suggested that successful Luhansk portion they would people 3 towns: Bilohorivka, Kreminna and Svatove.
President Zelensky has appealed to Western countries to hurry sending dense weaponry to Ukraine to assistance Ukraine repel Russia's expected offensive. The US agreed past week to nonstop long-range missiles that volition alteration Ukraine to treble its onslaught range.
The Russian defence curate warned that Western dense weapons were drafting Nato countries into the struggle and "could pb to an unpredictable level of its escalation".