'Resistance for Ukrainians is part of their soul' - Ukraine rejects ultimatums as conflict intensifies

Slava Chikov, left, covers the shattered window of his living room with a plastic sheet in a building damaged by a bombing the previous day in Kyiv, Ukraine, Monday, March 21, 2022. As Russia intensified its effort to pound Mariupol into submission, its ground offensive in other parts of Ukraine has become bogged down. Western officials and analysts say the conflict is turning into a grinding war of attrition, with Russia bombarding cities.(AP Photo/Vadim Ghirda)

Ukraine said it would not accept ultimatums from Russia after Moscow demanded it stop defending besieged Mariupol, where hundreds of thousands of civilians are suffering through Russian bombardments laying waste to their city.

Mariupol has become a focal point of Russia's assault on Ukraine, but attacks were also reported to have intensified on the country's second city Kharkiv on Monday.