Russia says it now controls Ukraine's Luhansk region, one of the two eastern regions that have been the focus of its invasion of Ukraine.
The announcement comes after Ukrainian troops withdrew from Lysychansk, an industrial city that had become the last major Ukrainian-controlled holdout in the region.
Together, Russian troops and a Russian-backed separatist militia "have established full control" over the city, a statement from Russia's defense ministry said. It represents "the liberation of the Luhansk People's Republic," the statement said, using the separatists' name for the self-proclaimed breakaway state.
Ukrainian troops had held out in this pocket of Luhansk for months, first in Sievierodonetsk, then Lysychansk. But with Russian troops pressing in on three sides, they faced the risk of encirclement and withdrew to the east, according to the General Staff of the Armed Forces of Ukraine.
"Continuing the defense of the city would have led to fatal consequences. In order to preserve the lives of Ukrainian defenders, a decision was made to withdraw," the armed forces said in a statement on Facebook.
The Russians had superiority in multiple facets of the fight, Ukrainian officials said, from artillery and air force to ammunition and personnel.
After the fall of nearby Sievierodonetsk late last month, Lysychansk had become the last major city under Ukrainian control in Luhansk, the easternmost region of Ukraine. Just a week ago, Serhiy Haidai, the exiled Luhansk regional governor, urged the city's residents to evacuate.
"They attacked the city with unexplainably brutal tactics," Haidai said over the weekend in a post on Telegram. "If in Sievierodonetsk, some houses and administrative buildings survived through a month of street fighting, then in Lysychansk the same administrative buildings were completely destroyed in a shorter period of time."
What the retreat from Lysychansk represents for Ukraine
Luhansk and Donetsk make up eastern Ukraine's Donbas region, where violence has been ongoing since long before Russia's invasion in February. Russian-backed separatists and Ukrainian forces have fought since 2014, after Russia's illegal annexation of Crimea.
On Feb. 21, Russian President Vladimir Putin set the stage for the full-scale invasion by recognizing separatist-controlled areas in Luhansk and Donetsk as independent and ordering Russian military forces there under what he called a "peacekeeping" mission.
In the months since, Russia scaled back the ambitions of its invasion and refocused its military efforts on eastern Ukraine, with parts of Donbas seeing the most intense fighting of the year so far.
Now, with Luhansk largely in Russian hands, the neighboring region of Donetsk could soon follow.
The last two Ukrainian-held major cities in Donetsk — Kramatorsk and Slovyansk — are just about 50 miles from Lysychansk. The other major cities in Donetsk, including Donetsk itself, along with Mariupol, have been controlled by Russians or Russian-backed forces for some time.
Kramatorsk and Slovyansk have endured Russian shelling and rocket fire for months, including the deadly attack on Kramatorsk's main train station in April that killed dozens of civilians.
If they fall, then the entire Donbas region would be effectively controlled by Russia — amounting to a demonstrable victory for Putin in a war that by all indications has dragged out longer than the Kremlin initially expected.
Putin has long prized the coal and steel-producing Donbas, which has a predominantly Russian-speaking population. The full capture would give Russia a strategic victory as well, expanding its control over Ukraine's southeast and further cementing the "land bridge" between Russian territory and Crimea.