Two Russian military commanders were killed in eastern Ukraine, Moscow’s Ministry of Defense said Sunday as Kyiv vowed its long-anticipated counteroffensive will free Russian-occupied parts of Ukraine.

The ministry said the commanders were fighting Ukrainian attempts to break through the frontline in Bakhmut.

Commander Vyacheslav Makarov of the 4th Motorized Rifle Brigade was wounded during the fighting and died while being evacuated off the battlefield, the ministry said.

Another high-ranking official — Col. Yevgeny Brovko, deputy commander of the Army Corps for Military-Political Work — died “heroically, suffering multiple shrapnel wounds,” the ministry said.

According to the ministry, Ukrainian troops have waged attacks in the north and south of Bakhmut over the last day, but haven’t broken through Russian defenses.

“All attacks by units of Ukraine’s armed forces have been repelled,” it said in a statement.

Ukrainian Deputy Defense Minister Hanna Maliar said on Sunday that troops “continue to move forward in the Bakhmut sector in the suburbs.”

“Our units captured more than ten enemy positions in the north and south of Bakhmut and cleared a large area of forest near Ivanivske. Enemy soldiers from different units were captured,” she said on Telegram.

Neither Russia nor Ukraine has been able to take full control over the highly contested city, though Moscow on Friday acknowledged its troops had fallen back north of Bakhmut as Ukraine amps up its attacks.

Kyiv has shied away from admitting its much-anticipated springtime counteroffensive has begun, but over the weekend, President Volodymyr Zelensky said with help from its Western allies, a Russian defeat in the war would be “irreversible.”

“Now is the time for us to determine the end of the war already this year, we can make the aggressor’s defeat irreversible already this year,” Zelensky said during a joint news conference with German Chancellor Olaf Scholz in Berlin.

Zelensky also thanked Germany for being a “true friend” during his visit after the German government announced $2.7 billion euro ($3 billion) of military aid to Ukraine, its biggest package since Russia first invaded the country last year.