KYIV, Ukraine (AP) — Russia claimed Friday that its forces captured a fiercely contested salt mining town, in what would mark a rare victory for the Kremlin after a series of setbacks in its war in Ukraine. Ukrainian authorities said the fight for Soledar continued.

Moscow has painted the battles for the town and nearby Bakhmut as key to capturing the entire eastern region of the Donbas — and also as a way to grind down the best Ukrainian forces and prevent them from launching counterattacks elsewhere. But that cuts both ways, and Ukraine has said that its fierce defense of the eastern strongholds has helped tie up Russian forces.

Since it invasion of Ukraine on Feb. 24, Moscow has prioritized taking full control of the Donbas — a region made up of the Donetsk and Luhansk provinces where it has backed a separatist insurgency since 2014. Russia has seized most of Luhansk, but about half of Donetsk remains under Ukraine’s control.

There have repeatedly been conflicting reports over who controls Soledar, where a bloody battle has raged for months. The Associated Press could not independently confirm either side’s claim.

“The liberation of the town of Soledar was completed in the evening of Jan. 12,” Lt. Gen. Igor Konashenkov, the Russian Defense Ministry’s spokesman, said, adding that the development was “important for the continuation of offensive operations in the Donetsk region.”

Taking control of the town would allow Russian forces “to cut supply lines for the Ukrainian forces” in Bakhmut and then “block and encircle the Ukrainian units there,” Konashenkov said.

But Serhii Cherevaty, a spokesman for the Ukrainian army in the east, denied the Russian Defense Ministry’s claim, telling the AP that, “There are still Ukrainian units in Soledar.”

Meanwhile, the Institute for the Study of War, a think tank in Washington, observed that the fall of Soledar wouldn’t mark “an operationally significant development and is unlikely to presage an imminent Russian encirclement of Bakhmut.”

The institute said that Russian information operations have “overexaggerated the importance of Soledar,” a small settlement, arguing as well that the long and difficult battle has contributed to the exhaustion of Russian forces.

White House National Security Council spokesman John Kirby on Thursday also downplayed the significance of potential Russian gains in the area.

“Even if both Bakhmut and Soledar fall to the Russians … it’s not going to have a strategic impact on the war itself,” Kirby said. “And it certainly isn’t going to stop the Ukrainians or slow them down in terms of their efforts to regain their territory.”

Just hours before Russia’s claim, Ukraine reported that there had been a heavy night of fighting but did not acknowledge loss of the town.

In a Telegram post early Friday, Ukraine’s deputy defense minister, Hanna Maliar, said that Moscow “had sent almost all (its) main forces” to secure a victory in the east.

“This is a difficult stage of the war, but we will win. There is no doubt,” Maliar added.

A Ukrainian officer previously told the AP that in the battle for Soledar, the Russians have first sent in soldiers, many from the private Russian military contractor Wagner Group, who take heavy casualties but exhaust the Ukrainian defenders. Then the Russians have sent in another wave of highly trained soldiers, paratroopers or special forces, said the Ukrainian officer, who insisted on anonymity for security reasons.

Konashenkov said that storming of Soledar became possible thanks to massive air and artillery strikes and airborne troops’ maneuvers to envelop the city. He didn’t mention the Wagner Group, which previously took credit for capturing Soledar. There have been signs of tensions between the army and the Wagner Group, led by millionaire Yevgeny Prigozhin.

Prigozhin angrily accused the Defense Ministry on Friday of “constantly trying to steal Wagner’s victory.”