The head of Russia's Wagner mercenary group said on Monday his fighters would leave Bakhmut by June 1 and transfer control to the Russian army, after claiming to have fully captured the city.
Both Wagner and the regular Russian army have said Bakhmut had fallen to them but Kyiv denies this, saying it is hanging on to a corner of the eastern Ukrainian city and that battles are ongoing.
"Wagner will leave Artemovsk from May 25 to June 1," Wagner boss Yevgeny Prigozhin said in an audio recording on Telegram.
Bakhmut was previously known as Artemovsk, in honour of a Soviet revolutionary, before Ukraine renamed it.
Prigozhin said the mercenaries had set up "defence lines" on the western outskirts of the city before a planned transfer of control to the Russian army.
"If the ministry of defence does not have enough personnel, we have thousands of generals," said Prigozhin, who has been embroiled in an increasingly public spat with the Russian military leadership.
Prigozhin has poured scathing criticism on Russian Defence Minister Sergei Shoigu and army chief of staff Valery Gerasimov, accusing them of being incompetent and causing Moscow's large-scale losses in the conflict in Ukraine.
Wagner fighters have spearheaded Russia's storming of Bakhmut and Prigozhin's influence has risen hugely during Moscow's Ukraine offensive.
On Saturday, he announced that Bakhmut had fallen to his fighters, speaking in a video against the backdrop of the ruined city.
He said then that Wagner fighters would pull out by May 25.
Russian President Vladimir Putin congratulated Wagner and the Russian army on the alleged conquest.
But Ukrainian President Volodymyr Zelenskyy said at the G7 summit on Sunday that Bakhmut was "not occupied" by Russia.