Fierce Fighting Erupts on Streets of Sievierodonetsk in Eastern UkraineFierce fighting has erupted on the streets of the eastern Ukraine city of Sievierodonetsk, with Kyiv’s forces trying desperately to fight off the Russian onslaught. Ukrainian President Volodymyr Zelenskyy characterized the situation as “indescribably difficult.” In a televised speech, he described capturing Sievierodonetsk as "a fundamental task for the occupiers" and said Ukraine was doing all it could to protect the city from a Russian takeover. Russian troops have entered the city, power and communications have been knocked out and "the city has been completely ruined," Sievierodonetsk Mayor Oleksandr Striuk told The Associated Press in a phone interview. "The number of victims is rising every hour, but we are unable to count the dead and the wounded amid the street fighting," the mayor said. Striuk said 12,000 to 13,000 civilians remain in the city that once had 100,000 residents. They are sheltering in basements and bunkers to escape the Russian assault. Striuk estimated 1,500 civilians in the city have died since the war began, from Russian attacks as well as from a lack of medicine or treatment. Sievierodonetsk, the last major Ukrainian-held population center in the eastern Luhansk province, has become the focus of Russian attacks as Moscow attempts to control the Donbas region after failing to topple Zelenskyy or capture the capital, Kyiv, during more than three months of fighting. Sievierodonetsk is about 140 kilometers from the Russian border. Luhansk Governor Serhiy Haidai said Russian troops "use the same tactics over and over again. They shell for several hours — for three, four, five hours in a row — and then attack. Those who attack die. Then shelling and attack follow again, and so on until they break through somewhere." Russian Foreign Minister Sergey Lavrov told France’s TF1 television Sunday that Moscow's "unconditional priority is the liberation of the Donetsk and Luhansk regions," saying that Russia sees them as "independent states." Zelenskyy was set Monday to address the European Council as he pushes for more help for Ukraine and pressure on Russia to end its invasion. The United States is continuing its arms shipments to Ukraine, but President Joe Biden said Monday that the U.S. will not send rocket systems that can reach Russia. European Council President Charles Michel said in a letter ahead of a two-day session that Ukraine is “showing incredible courage and dignity in the face of the Russian aggression and atrocities.” “One of our most pressing concerns is assisting the Ukrainian state, along with our international partners, with its liquidity needs,” Michel said. “We will also discuss how best to organize our support for Ukraine's reconstruction, as a major global effort will be required to rebuild the country.” Michel said the meetings would include addressing high energy prices linked to the conflict and a need to “accelerate our energy transition” in order to phase out European dependence on Russian fossil fuels, as well as discussing ways to deal with issues of food security and price increases. Some information in this report came from The Associated Press, Agence France-Presse and Reuters.