CHICAGO - Ukrainian President Volodymyr Zelenskyy claims a surprise offensive has already freed 30 towns and villages from Russian control.
Russia's state-controlled media so far do not dispute the claim, with some conceding that Ukrainian forces have scored significant gains.
Ukrainian-Americans in Chicago are cheering the news, but have learned from friends and relatives in Ukraine that the advances come at a dreadful cost in human life.
"We're getting reports from the hospitals about the massive casualties and so forth. But victory, the price of victory is very high," said Pavlo Bandrhiskey, of the Ukrainian Congress Committee of America.
Russia's top propaganda channels, which often air bombastic claims of inevitable victory, were unusually grim in Friday night's broadcasts from Moscow, according to translations provided by Julia Davis's Russian Media Monitor.
Western journalists say it's difficult to determine exactly what's happening at the battlefront, since the Ukrainian military has clamped tight restrictions on the flow of information.
But satellite photos and geo-located video on social media indicate the Ukrainians in places have driven 50 kilometers or more past previous front lines and may be on the verge of surrounding major Russian deployments.
"We're also seeing Ukraine not only hold the line in the Donbas and in the northeast, but, as you noted, make a significant advance," said U.S. Secretary of State Antony Blinken.
"We can't really predict how long things are gonna last or what the outcome is gonna be. We can only do what we've done thus far in continuing to support Ukraine," said U.S. Secretary of Defense Lloyd Austin.
The defense secretary urged NATO allies to help supply winter uniforms for Ukrainian fighters, underscoring the belief on both sides that despite the recent gains, what lies ahead is a long war of attrition.