KYIV, Ukraine (AP) — Up to 200 Ukrainian soldiers are being killed every day in Russia’s military onslaught, according to an adviser to Ukraine’s president — and only more and more advanced Western weaponry will turn back the Russian offensive, reduce the casualties and force Moscow to the negotiating table.

Mykhailo Podolyak told the BBC in an interview aired Thursday that the daily loss of between 100 and 200 Ukrainian soldiers is the result of a “complete lack of parity” between Ukraine and Russia, which has “thrown pretty much everything non-nuclear at the front” in its bid to advance in Ukraine’s eastern Donbas region and beyond.

Recently Ukrainian President Volodymyr Zelenskyy put the daily death toll at up to 100, but Podolyak said it had grown. Ukrainian officials have pointed at the mounting losses to emphasize their demand for more Western weapons, which have been critical to the country’s unexpected success in holding off the larger and better equipped Russian forces.

After a bungled attempt to overrun Kyiv in the early days of the war, Russia shifted its focus to the Donbas region of coal mines and factories. But its progress there has been plodding.

Podolyak said delivery of state-of-the-art artillery systems would not only curb Ukraine’s death toll, it would help its forces reclaim seized territory.

“There’s something really important that our partners need to understand, and that’s until Russia suffers a serious military defeat, no form of dialogue will be possible, and they will continue to be able to try and take parts of our country,” he said.

Podolyak also addressed Western fears that Western rocket launchers in the hands of Ukraine’s forces would be used to strike targets inside Russia and potentially escalate the conflict to a wider conflagration, saying that “it won’t happen.”

Street battles

The slog in the Donbas continued Friday, with a Ukrainian governor saying forces are fighting “for every house and every street” in Sievierodonetsk, the recent focus of clashes.

Sievierodonetsk is in the last pocket of the Luhansk region that has not yet been claimed by Russia.

Luhansk Gov. Serhiy Haidai told The Associated Press that Ukrainian forces retain control of the industrial zone on the edge of the city and some other sections, and painstaking block-by-block fighting continues.

Zelenskyy said late Thursday that while the situation in the Donbas is static, Ukrainian forces had made some progress in the Zaporizhzhia region in the south, where the Ukrainian troops have been able to “spoil the plans of the occupiers.” He gave no specifics.

Britain calls trail of its citizens a ‘sham’

The British government said Russia must take responsibility for the “sham trial” of two Britons and a Moroccan who were sentenced to death for fighting against Russian forces in Ukraine.

Britons Aiden Aslin and Shaun Pinner and Moroccan Brahim Saadoun were convicted by a court run by pro-Moscow separatist authorities in the self-proclaimed Donetsk People’s Republic, which is not recognized internationally.

Separatist authorities argued that the men were “mercenaries” not entitled to the usual protections accorded prisoners of war.

Aslin’s and Pinner’s families have said that the two men were long-serving members of the Ukrainian military. Saadoun’s father told a Moroccan online newspaper that his son is not a mercenary and that he holds Ukrainian citizenship.

Government minister Robin Walker said Friday that it was “an illegal court in a sham government” but that the United Kingdom (UK) would use “all diplomatic channels to make the case that these are prisoners of war who should be treated accordingly.”

British Foreign Secretary Liz Truss is due to speak to her Ukrainian counterpart Dmytro Kuleba later Friday about the case. The UK has not announced any plans to speak to Russian officials — and it does not recognize the self-proclaimed Donetsk republic and will not officially contact the authorities there.

Russian Foreign Ministry spokeswoman Maria Zakharova said the ministry has so far not received any specific appeals about the men from Britain and as such, “we can make an unambiguous conclusion that until now the fate of these citizens was not of interest to London.”