But he pledged late on Sunday to regain control of the lost territory with the help of long-range Western weapons.
Russia said its capture of Lysychansk less than a week after taking neighbouring Severdonetsk gave it full control of Luhansk – a political win that meets a key Kremlin war goal. The battlefield focus now shifts to the neighbouring Donetsk province which, together with Luhansk, makes up what is known as the Donbas region.
“If the commanders of our army withdraw people from certain points at the front, where the enemy has the greatest advantage in firepower, and this also applies to Lysychansk, it means only one thing,” Zelenskyy said in his nightly video address.
“That we will return thanks to our tactics, thanks to the increase in the supply of modern weapons.”
This included long-range weapons such as the United States-supplied HIMARS rocket launchers, he said.
Since abandoning an assault on the Ukrainian capital, Kyiv, Russia has concentrated its military operation on the industrial Donbas heartland, where Moscow-backed separatist proxies have been fighting the Ukrainian army since 2014.
Russia says it is capturing the Luhansk region in order to give it to the self-proclaimed Russian-backed Luhansk People’s Republic, whose independence it recognised before invading Ukraine on February 24.
Ukraine’s military command said its forces had been forced to retreat from the city.
While Russia would try to frame its advance in Luhansk as a significant moment in the war, it came at a high cost to the Russian military, said Neil Melvin of the London-based think tank, RUSI.
“Ukraine’s position was never that they could defend all of this. What they’ve been trying to do is to slow down the Russian assault and cause maximum damage, while they build up for a counteroffensive,” he told the Reuters news agency.
West of Lysychansk in the Donetsk region, at least six people were killed when the city of Sloviansk was hit by powerful shelling from multiple rocket launchers on Sunday, local officials said.
Zelenskyy said at least 20 more were wounded in Sloviansk and added that Russia had also “brutally” struck the cities of Kharkiv and Kramatorsk with rocket attacks.
Russia’s defence ministry also said it had struck the military infrastructure of Kharkiv, Ukraine’s second-largest city in the northeast.
Far from the fighting in the east, Australian Prime Minister Anthony Albanese on Sunday visited a town near the Ukrainian capital that was severely damaged early in the war. Albanese called the destruction in Irpin “devastating”.
“These are homes and these are livelihoods and indeed lives that have been lost here in this town,” he said, adding that his government would provide Ukraine with more armoured vehicles and would tighten sanctions against Russia.
Meanwhile, the exiled mayor of the Russia-occupied city of Melitopol said on Sunday that Ukrainian rockets destroyed one of four Russian military bases in the city.
Attacks were also reported inside Russia, with the governor of the Belgorod region saying fragments of an intercepted Ukrainian missile killed four people on Sunday.
“The sound was so strong that I jumped up, I woke up, got very scared and started screaming,” a Belgorod resident told the Reuters news agency, adding the blasts occurred at about 3am (00:00 GMT).
Moscow has accused Kyiv of numerous attacks on Belgorod and other areas bordering Ukraine. Kyiv has never claimed responsibility for any of these incidents.
Kursk regional governor Roman Starovoit said the town of Tetkino, on the Ukraine border, came under mortar fire.