The eastern Ukrainian city of Bakhmut has been the site of fierce fighting between Ukrainian and Russian forces for months.
Ukrainian President Volodymyr Zelensky on Sunday appeared to acknowledge the loss of the eastern city of Bakhmut to Russian forces.
When asked during the G7 summit in Hiroshima if Ukraine still controls the city, Zelenskyy replied, "I think no."
"You have to understand that there is nothing," Zelensky said, referring to Russia's actions. "They destroyed everything."
The Russian Defense Ministry on Saturday announced that its troops, along with Wagner mercenaries, have taken control of the flashpoint city.
Bakhmut, which is located in Ukraine's Donetsk province, has been the site of fierce fighting between Ukrainian and Russian forces for months. Russia controls around half of the province and claimed to have annexed it in the autumn of 2022.
"As a result of offensive actions by Wagner assault units, supported by artillery and aviation of the Southern Group of Forces, the liberation of Artyomovsk has been completed," the Russian Defense Ministry said, referring to Bakhmut by its Soviet-era name.
The head of the Wagner mercenary group, Yevgeny Prigozhin, also reported the capture of Bakhmut on Saturday.
Russian news agency Interfax reported that President Vladimir Putin had congratulated troops for capturing the city.
The claim that the city has been captured was disputed on Saturday by Ukrainian officials, who said fighting to control the city continued.
Ukraine's Deputy Defense Minister Hanna Maliar said heavy fighting was continuing.
"The situation is critical," she said. "As of now, our defenders, control certain industrial and infrastructure facilities in this area."
Serhiy Cherevatyi, a spokesman for Ukraine's eastern command, told the AP news agency that Prigozhin's claim "is not true. Our units are fighting in Bakhmut."
While the General Staff of the Armed Forces of Ukraine said in a statement on Facebook that "heavy battles for the city of Bakhmut do not stop."
Over 70,000 people lived in Bakhmut before Russia invaded Ukraine in early 2022. The fight for control of the city erupted last August. Since then, Russian forces have besieged Bakhmut, a city under Kyiv's control within the industrial Donbas area.
The brutal fight for the city has been raging for over 9 months and descended into a vicious battle of attrition involving trench warfare.
No other city has been under siege for this long and both Ukraine and Russia have both suffered heavy losses.
Bakhmut is considered to be strategically important due to its location along the E40 highway — which connects Ukraine's second-largest city, Kharkiv, with the Russian city Rostov-on-Don.
Russian capture of the city would allow it to move on to Ukrainian cities further west such as Slovyansk and Kramatorsk, an important industrial hub and administrative center in the Donetsk region.
This, in turn, would bring Russia closer to its goal of conquering the entire Donetsk area.