<b>Live updates: follow the latest news on </b><a href="https://www.thenationalnews.com/world/2022/02/18/russia-ukraine-latest-news/"><b>Russia-Ukraine</b></a> Russia's prolonged assault on the port of Mariupol is bogging down its wider offensive in <a href="https://www.thenationalnews.com/tags/ukraine/" target="_blank">Ukraine</a>, British intelligence said on Monday as the southern city refused to surrender to Moscow’s troops. Ukraine said the city was being pounded by bombs and missiles, including by Russian Tu-22M3 bombers, as the Kremlin pursues what would be a significant victory by capturing Mariupol. Troops defending Mariupol defied a demand to surrender on Sunday as <a href="https://www.thenationalnews.com/tags/russia/" target="_blank">Russia</a> carried out what Ukraine said were assault operations near the seaport and the Azovstal steel plant. <a href="https://www.thenationalnews.com/tags/ukraine" target="_blank">Britain</a>’s Defence Ministry said in a regular intelligence update that Russian commanders “will be concerned by the time it is taking to subdue Mariupol”, the scene of some of the heaviest fighting of the seven-week invasion. “Concerted Ukrainian resistance has severely tested Russian forces and diverted men and materiel, slowing Russia’s advance elsewhere,” the ministry said. It accused Russia of targeting populated areas in a manner similar to its assaults on Chechnya in 1999 and Syria in 2016 and thereby going back on promises that it would not attack civilians. Ukrainian President Volodymyr Zelenskyy said in an overnight address that Russian troops were “destroying Mariupol” and “want to wipe out other cities and communities” in the eastern Donetsk and Luhansk regions. “Russian troops are preparing for an offensive operation in the east of our country,” he said. “It will begin in the near future. They want to literally finish off and destroy Donbas.” Russia claims it is seeking to liberate Mariupol, which has become synonymous with the humanitarian crisis unleashed by the war, from what it describes as nationalists and foreign mercenaries. Ukraine, which has said that a massacre there could call a halt to tentative peace negotiations between the two sides, said it had failed to reach agreement with Russia on the opening of humanitarian escape routes on Sunday. Control of the south coast is regarded as important because it would connect Russian-occupied territories in Donbas and Crimea. Meanwhile, Russian shelling killed five people in Kharkiv on Sunday, Mr Zelenskyy said, with at least 15 others reported wounded. He claimed artillery had been fired at residential neighbourhoods in a days-long attack that had killed at least 18 people in the city. In the west, which has been a relative safe haven from the fighting, Lviv Mayor Andriy Sadovyi reported five missile strikes across the city on Monday morning. There was no immediate word on casualties. Mr Zelenskyy renewed his calls for “greater speed from western countries” in raising economic pressure on Russia and delivering weapons to Ukraine. “Those who have the weapons and ammunition we need and delay their provision must know that the fate of this battle also depends on them,” he said. “The fate of people who can be saved.”