Ukraine's Zelensky has previously signaled he hopes to get territory in the Donbass back from Russia by swapping it in return for Kursk. Ukraine's ambitious and high-risk Kursk offensive began in early August, and has resulted in dozens of towns and hundreds of square kilometers brought under Ukrainian military occupation.
But in a status update issued Friday, Russia's military declared that most of the territory has since been taken back, saying that nearly 65% of what was lost has been regained.
"More than 800 square kilometers [309 square miles] have been liberated, which amounts to about 64% of the territory initially occupied," Sergei Rudskoi, first deputy head of Russia's General Staff, told a military newspaper.
"Currently the initiative in the Kursk region is fully on our side. Russian forces are advancing in all areas," Rudskoi described to Krasnaya Zvezda.
He also said that around "around 75%" of Ukraine's Donetsk, Zaporizhzhia and Kherson regions' are held by Russia, in Ukraine's east, and that Ukrainian forces at this point control "less than 1%" of the eastern Luhansk region.
Rudskoi further said that throughout last year Russia took "almost 4,500 square kilometers of territory" in Ukraine, and dubbed it a "breakthrough" year.
"The Kyiv regime will not be able to significantly change the situation on the battlefield any more," Rudskoi added.
Ukraine's cross-border offensive into Kursk was always meant to force the Kremlin to divide its forces in order to defend its land, but this by and large has not happened - or in other words Putin has not taken the bait.
Instead, there have long been reports that thousands of North Korean troops have assisted Russian forces in seeking to take it back. But Moscow hasn't appeared in a hurry, and has not sacrificed its gains in Donetsk to make it happen.
Russia's defense ministry has made frequent statements highlighting Ukraine's immense losses trying to hold the seized Kursk territory over the last several weeks, stressing that it is Zelensky who has gotten the worse end of the gambit.
Some Russian sources have claimed Ukraine has lost some 50,000 troops during the invasion of Russian territory. The huge cross-border operation has been pushed back slowly by the Russian side, and the momentum is clearly in Moscow's favor.