UN Humanitarian Coordinator for Ukraine Denise Brown has denounced Russia's attack on Ukrainian cities on Wednesday morning.

"The attacks have led to a distressing number of civilian casualties and have massively disrupted essential services, including electricity, water and gas supplies, especially in Mykolaiv City and Ukraine's capital, Kyiv, when they are much needed this cold winter. Millions of people rely on these services for heating, cooking and transportation. They are critically important to ensure health and education facilities are functional," she said in a statement published on the website of United Nations Ukraine.

The official also emphasized that "Ukrainians should live without fear of attacks disrupting their lives."

Humanitarians have mobilized emergency response in Kyiv and Mykolaiv, delivering repair materials and psychosocial assistance to those affected, Brown said.

"Repeated attacks damaging civilian infrastructure and causing injuries and deaths to civilians indicate a concerning pattern of harm and international humanitarian law violations. Civilians must be spared from violence," she said.