Representative Elissa Slotkin (D-MI) told CNN Wednesday that the toll was “huge,” and the officials had also made it clear that “over 80% of [Russia’s] land forces are bogged down, and they’re tired.”

The update came just a week after CIA Director William Burns said an estimated 15,000 Russian soldiers had been killed, and 45,000 were likely wounded—it’s a military rule of thumb that the tally of wounded individuals outnumbers death tolls by three to one.

However, Ukrainian President Volodymyr Zelenskyy claimed on Tuesday that “nearly 40,000” Russian soldier had died in the war, and “tens of thousands more have been injured or maimed.”

Slotkin’s disclosure implies that somewhere around 19,000 Russians have lost their lives in the invasion by the aforementioned rule of thumb.

She was right to call that a huge toll.

Russia only launched its full-scale invasion of Ukraine just over five months ago. When the Soviet-Afghan War ended after nine years in 1989, the official Soviet death toll was 15,000.

Russia sent at least 150,000 troops to Ukraine at the start of the war, so if the 75,000 figure is accurate, that’s as much as half the total deployed forces.

How accurate are these figures?

However, it is very difficult to get accurate death tolls from the Ukraine war, as is usually the case in times of conflict.

Civilian death tolls are hard to establish because independent human rights monitors often have trouble accessing massacre sites and interviewing people there—and “combatant deaths are particularly vulnerable to misinformation,” conflict researcher Shawn Davies told Fortune in March.

Moscow last gave its own estimate of dead Russian military personnel in late March, when authorities there said 1,351 had perished. However, a Russian court banned distribution of such information last month, claiming it amounted to revealing military secrets.

Ukraine isn’t exactly forthcoming about its own military death toll, either. Kyiv said in early June that around 10,000 of its fighters had lost their lives, with around 30,000 injured.

On Monday, the United Nations’ human rights commissioner said 5,237 civilians had been killed during the war—including 348 children—and 7,035 injured. That’s just verified deaths and injuries, however, and the U.N. said “the actual figures are considerably higher.”

The BBC reported Thursday that Russia’s offensive in eastern Ukraine had stalled, thanks to Western shipments of sophisticated weaponry to Kyiv.

Meanwhile, British defense and intelligence officials said Thursday that a Ukrainian counteroffensive in the south of the country had nearly isolated the Russian-occupied city of Kherson—if Ukraine re-takes that city, it will be severely embarrassing for Vladimir Putin’s regime.

“I think that what we heard very firmly from President Zelenskyy and reinforced today is that the Ukrainians really want to hit Russia in the teeth a few times before the winter comes, put them in the best position possible, particularly hitting them down south,” Slotkin told CNN.

She added that there was bipartisan support in the U.S. for sending Ukraine long-range ATACMS missiles.

However, the White House recently indicated that it’s not keen on that idea, because the Ukrainians could use the missiles to strike within Russian territory.