KYIV - On Monday, Ukrainian forces faced relentless Russian attacks on Bakhmut in Ukraine's eastern Donetsk region, with both sides reporting rising enemy casualties as they fought across a small river that bisects the ruined town and now marks the front line.

Ukraine's President Volodymyr Zelenskiy said late Sunday that his forces had killed over 1,100 Russian soldiers in the last few days while fighting for control of Bakhmut.

"We managed to kill more than 1,100 enemy soldiers in the Bakhmut sector alone in less than a week, starting on March 6th, Russia's irreversible loss, right there, near Bakhmut," Zelenskiy said in his nightly video address.

He added that Russian forces suffered 1,500 "sanitary losses," or soldiers who were injured severely enough to keep them out of action.

Russia's defense ministry said earlier in the day that its forces had killed more than 220 Ukrainian service members in the Donetsk region in the previous 24 hours.

Reuters was unable to independently verify battlefield reports, and neither side provided information on their own casualties.

Ukraine forces control the west of the nearly deserted mining town of Bakhmut, while Russia's Wagner mercenary group controls the majority of the east, with the Bakhmutka River, which runs through the town, marking the front line, according to a weekend update from British intelligence.

Russian forces are continuing their offensive operations in the Donetsk region's Lyman, Bakhmut, Avdiivka, Maryinka, and Shakhtar areas, Ukraine's military said on Monday, adding that Ukrainian forces had repelled 102 attacks in those areas in the previous day.

Ukraine repelled attacks near four settlements in the Bakhmut area, where at least 11 settlements were targeted the previous day, according to the military.

"The enemy never stops trying to capture Bakhmut," it said.

Wagner founder Yevgeny Prigozhin described the situation in Bakhmut as "tough, very tough" on Sunday.

"The fighting gets more intense as we get closer to the city centre. Ukraine continuously adds reserves. However, we will continue to advance "Prigozhin stated in remarks made public by his press office.

He added that Russian army personnel provided ammunition support for his troops.

"We received 15 truckloads yesterday, and 12 today. And I believe we'll keep getting them "He added that his fighters and Russian soldiers had not engaged in combat.

Prigozhin had earlier claimed that Russia's top brass was purposely depriving his troops of ammunition, a claim that was denied by the defense ministry.

Prigozhin said Wagner "will begin to reboot" and start hiring once Bakhmut is captured. Wagner has opened recruitment centres across 42 cities to replenish its ranks.

Although Bakhmut's strategic value is debatable, Russia views its capture as a step toward the war's main objective of capturing the entirety of Ukraine's Donbas industrial region. The war is now in its second year. The Donbas consists of the regions of Donetsk and Luhansk.

After giving early indications that it intended to leave Bakhmut, Ukraine has decided to continue fighting there in order to wear down Russia's best units in preparation for a spring offensive.

Analysts predict that a counteroffensive by the Ukrainians will start in earnest between April and May as the weather improves and more military aid, such as powerful Leopard and Challenger tanks, is delivered.

According to decorated Ukrainian tank brigade commander Leonid Khoda, the use of Western tanks will fundamentally alter military strategy.

"Everyone is waiting, including the 1st Tank Brigade. We recently sent personnel to learn how to use the (Leopard) 2A6 "said Khoda, who is in charge of the 1st Siversk Tank Brigade, which is engaged in combat in Donetsk's south.

In other news, the governor of Russia's Belgorod region said on Monday that four missiles were shot down by its air defence over the Ukrainian border region. He added that one person was hurt.

Although Vyacheslav Gladkov declined to identify the perpetrators, he has previously charged Ukrainian forces on the other side of the border with carrying out attacks akin to these.

Donetsk, a city in eastern Ukraine that is under the control of Russia, was shelled four times on Sunday; residential areas and power lines were damaged, and Russian-installed officials assigned the blame to Ukraine.

Attacks inside Russia and on Ukrainian territory under Russian control are almost never blamed on Ukraine.

Dmytro Kuleba, the foreign minister of Ukraine, has urged Germany to begin training Ukrainian pilots to fly Western fighter jets and to expedite ammunition deliveries.

Kuleba made it clear that he did not anticipate that Western allies would grant Ukraine's request for aircraft any time soon, but he advised pilots to be prepared for the eventuality.

According to a senior EU official, the EU may soon add an additional 3.5 billion euros to a fund used to buy weapons for Ukraine.