The dawn deadline Russia gave determined Ukrainian soldiers to surrender and lay down their weapons in Mariupol passed without incident on Sunday morning, as Vladimir Putin’s increasingly sloppy troops closed in on the strategic port city.

Russia’s defense ministry, still reeling from the loss of 8th Army Major General Vladimir Frolov in combat on Saturday, was just as determined, threatening to “eliminate” any Ukrainian and foreign troops trying to hold on to the battered city.

Russia has made considerable gains on the city after spending weeks trying to wipe it off the map. Western intelligence officials said it could fall to Russia soon, providing a key land bridge between Crimea and the eastern separatist regions it so desperately wants to take.

President Volodymyr Zelensky confirmed that his fighters had only a small part of the city under their control. “The situation is very difficult in Mariupol,” he said overnight Sunday, according to CNN. “Our soldiers are blocked, the wounded are blocked. There is a humanitarian crisis… Nevertheless, the guys are defending themselves.”

Russia warned in a statement Sunday that there were “up to 400 foreign mercenaries who joined the Ukrainian forces” huddling inside a steel plant, including many Europeans and Canadians who had come to support Ukrainian troops. “In case of further resistance, all of them will be eliminated,” the statement said.

Further north, heavy bombardment on Ukraine’s second city Kharkiv killed and injured dozens of emergency workers and civilians, according to CNN which cited Kharkiv Regional Military Administration head Oleg Sinegubov. “They are currently receiving treatment in the hospital.” Sineguboy wrote on Telegram. “Thirty-one people were injured in Russian shelling, including four children.”

He also wrote that Russian forces were using aerial bombardment, after being pushed back on land. “The enemy cannot approach Kharkiv as our armed forces are holding strong positions and are even advancing in some directions,” he said. “Therefore, Russians resort to shameful shelling of residential neighborhoods.”

Bolstered by the gains in Mariupol and undeterred by the losses, Russian troops renewed efforts on Kyiv early Sunday, striking Brovary to the east. On Saturday, attacks on strategic targets further west in largely untouched Lviv also signaled that the war is at a turning point. Citing the Institute for the Study of War, the Washington Post reported Sunday that Russian troops were likely “setting conditions for a larger-scale, better-coordinated offensive.” Simply put, the worst may be yet to come.