Ukraine's President Volodymyr Zelenskyy acknowledged on Sunday that Kyiv's forces had withdrawn from the strategic city in the eastern Donbas region after a grinding Russian assault. But he vowed to regain control over the area with the help of long-range Western weapons. Moscow said the capture of Lysychansk meant it had "liberated" the Luhansk region, less than a week after taking neighbouring Sievierdonetsk.  Lysychansk was the last Ukrainian stronghold in Luhansk, a key target for Russia. Its capture will provide Moscow's troops with a stronger base from which to press their advance in the Donbas — the old industrial region of mines and factories that Vladimir Putin is bent on capturing. The battlefield focus now shifts to the neighbouring Donetsk region, where Kyiv still controls swathes of territory. Ukraine will not 'give anything up', says Zelenskyy In his nightly address on Sunday evening, Zelenskyy acknowledged the withdrawal, but was adamant Ukraine would never "give anything up". "We will return, thanks to our tactics, thanks to the increase in the supply of modern weapons," he said. The Ukrainian president said Russia was concentrating its firepower on the Donbas front, but Ukraine would hit back with long-range weapons such as the US-supplied HIMARS rocket launchers. "The fact that we protect the lives of our soldiers, our people, plays an equally important role. We will rebuild the walls, we will win back the land, and people must be protected above all else," he said. Zelenskyy insisted that Kyiv's forces were "making progress" elsewhere, in the areas around Kharkiv in the north-east, and Kherson in the south. "The day will come when we will say the same thing about the Donbas", he added. Since abandoning its assault on the capital Kyiv, Russia has focused its military operation on the industrial Donbas heartland that comprises the Luhansk and Donetsk regions, where Moscow-backed separatist proxies have been fighting Ukraine since 2014. Moscow said it will give Luhansk to the self-proclaimed Russian-backed Luhansk People's Republic whose independence it recognised on the eve of the war. But Zelenskyy poured scorn on Moscow's achievements. "What is all this for? For the sake of insane propagandists to be able to show a Russian or Soviet flag on the ruins somewhere in their broadcasts. There is simply no other answer," he said in his Sunday night address. No let-up in Russian assault on east The Russian army continued to pound eastern Ukraine on Monday, advancing its plan to conquer the entire Donbass region after taking Lysychansk. In Sloviansk, a town of about 100,000 inhabitants before the war, Russian strikes killed six people on Sunday, including a nine-year-old girl. The Ukrainian authorities are now calling on residents to leave the region, while the front line is only a few kilometres away. Ukrainian forces appear to be trying to defend a line between Siversk — about 20 kilometres west of Lysychansk — and Bakhmut, to protect Sloviansk and Kramatorsk. "The enemy has intensified its shelling on our positions in the direction of Bakhmut," the Ukrainian army headquarters confirmed in its first update on Monday morning. Monday sees the start of the  Ukraine Recovery Conference in Lugano which President Zelenskyy said can "become an essential step for Ukraine's reconstruction". The conference will be jointly hosted by Switzerland and Ukraine from 4-5 July and is billed as an opportunity for Ukraine to work with international partners on a plan to recover and rebuilt the country.