Ukrainian electricity supplies are under control despite a series of Russian attacks on power-generating infrastructure and there is no need to panic, the energy ministry said on Saturday.
Separately, the head of DTEK, the country's largest private energy company, said there was no need for people to leave Ukraine.
Russian missile strikes have crippled almost half of Ukraine's energy system and Kyiv authorities said on Friday that a complete shutdown of the capital's power grid was possible.
"Denying the panicky statements spread by social networks and online media, we assure you that the situation with the energy supply is difficult, but under control," the energy ministry said in a statement.
Authorities across the country have scheduled blackouts to help the repair effort, it said, urging families to cut their energy consumption by at least 25%.
Ukraine's national grid operator Ukrenergo said while planned blackouts will take place in all regions on Sunday, it does not envisage unexpected emergency shutdowns of electricity.
"We continue to work to return the light to Ukrainians," the company said in a statement late on Saturday on the Telegram messaging app.
"It is difficult, sometimes longer than we expected, but we find solutions."
Ukraine President Volodymyr Zelensky accused Russia last month of trying to destabilise the country by forcing millions to flee westwards, creating a refugee crisis for the European Union.
DTEK CEO Maxim Timchenko said the armed forces, the energy industry and individual Ukrainians were working miracles to maintain supplies.
"That is why there is no need to leave Ukraine today," a company statement cited him as saying.
Zelenskiy said on Saturday the supply problems were worst in and around Kyiv as well as in six other regions.
"We are working throughout the country to stabilise the situation," he said in a video address.