Operations to defend the embattled eastern city of Bakhmut will go on, and are backed by senior generals, Ukraine President Volodymyr Zelensky has said.
Western analysts suggested at the weekend that Ukraine was probably withdrawing some of its troops, as Russian forces close in on the city.
Moscow has been trying to take Bakhmut for months, as both sides suffer heavy losses in a grinding war of attrition.
A local official says there has been street fighting in recent days.
But Deputy Mayor Oleksandr Marchenko said at the weekend that Russia had not yet gained control of the city.
Meanwhile Yevgeny Prigozhin, head of the Wagner private army involved in the Russian campaign, has complained of a lack of ammunition amid apparent friction between his fighters and regular Russian forces.
He also says his representative had been barred from a Russian military headquarters.
Analysts say Bakhmut has little strategic value but has become a focal point for Russian commanders who have struggled to deliver any positive news to the Kremlin.
Capture of the city would bring Russia slightly closer to its goal of controlling the whole of Donetsk region, one of four regions in eastern and southern Ukraine it annexed last September after referendums widely condemned outside Russia as a sham.
Mr Zelensky said in his evening address that he had discussed Bakhmut with senior generals.
"[They] responded not to withdraw, but to strengthen [our defences]," he said.
"The command unanimously supported this position. There were no other positions. I told the commander in chief to find the appropriate forces to help our guys in Bakhmut."
The comments followed a report by the German newspaper Bild quoting Ukrainian government sources that armed forces commander Valery Zaluzhny had disagreed with Mr Zelensky about the operation several weeks ago, recommending a retreat from the city.
Most defenders shared Gen Zaluzhny's view, the paper added.
And at the weekend the US-based think tank the Institute for the Study of War (ISW) said Ukrainian troops were probably conducting a "limited fighting withdrawal" while "continuing to inflict high casualties" on the Russians.
Ground forces commander Olexandr Syrsky, quoted on a visit to the front line on Sunday by Ukrainska Pravda newspaper, said the fighting in Bakhmut had reached the "highest level of tension".
"The enemy has been throwing extra Wagner forces into the battle," he said. "Our troops have been courageously defending our positions in the north of Bakhmut, trying to prevent the encirclement of the city."