Ukrainian troops conducting weekend exercises near the small town of Siversk, in the country's east, said they were preparing to defend one of the possible targets of a new Russian offensive.
Siversk, which had a pre-war population of 10,000, is 35 kilometres (21 miles) north of Bakhmut—scene of fierce fighting in recent weeks—and on a direct road to another of the key towns in the Donetsk region, Sloviansk.
"If they occupied Bakhmut, then we would be semi-encircled, because on the left side we have the Siverskyi Donets river, and the enemy will advance from the right, and it is possible to cut us off if they reach the Bakhmut highway," said the deputy Siversk battalion commander, who used the nom-de-guerre "Han".
Ukrainian forces have appealed for more advanced weapons from Kyiv's Western allies to help defend Bakhmut, which is being attacked by Russia's Wagner mercenary group.
One soldier defending Siversk said their mostly Soviet-era artillery was outgunned by the enemy.
"We have one artillery attack from our side, and the Russians can do it five times more," said 30-year-old Stefan. "It's very difficult for the guys who are standing, especially at the first line (of defence), they feel it too much."
Capturing Bakhmut would give Russian forces a stepping stone to advance on two bigger cities further west, Kramatorsk and Sloviansk.
But Ukraine and its Western allies say success there would be a largely Pyrrhic victory for Moscow, given the time taken and losses sustained.