Ukraine recorded a new daily high of more than 20,000 coronavirus cases.
Health Minister Maxim Stepanov says 20,341 new infections were registered in the previous day, nearly 500 more than the record on Friday.
Ukraine began vaccinations late February, but only about 230,000 people have received the shots because of widespread reluctance. The sharply rising numbers prompted the mayor of the capital Kyiv to order schools and public transportation closed for two weeks starting Monday.
Overall, more than 1.7 million infections and 34,000 confirmed deaths have been recorded during the pandemic.