Ukraine's daily electricity imports will reach their highest this year on Tuesday after a string of Russian missile strikes on critical infrastructure caused blackouts in many regions, the energy ministry said.

The sweeping attacks, the biggest of which came on Friday, have caused major damage to generating and transmission facilities, forcing Kyiv to halt power exports and rely on imports.

Power imports are expected to reach 18,649 megawatt hours (MWh) on Tuesday, up from 14,900 MWh on Sunday, the ministry said in a statement.

By contrast, Ukraine had exported 3,300 MWh the day before the first wave of Russian attacks on March 22.

Ukraine has been connected to the European Union's united grid since the first weeks of Russia's full-scale invasion in February 2022. The imports come from Romania, Slovakia, Poland, Hungary and Moldova, the Ukrenergo grid operator told Reuters.

Ukraine, which has an extensive civilian nuclear energy sector, was a net exporter of power before the invasion and subsequent Russian occupation of Europe's largest nuclear power plant.

There are 200,000 residents of the northeastern border city of Kharkiv and parts of southeastern Zaporizhzhia region still without electricity supply since last Friday's attacks.

Emergency power outages have also been introduced in Ukraine's Black Sea port city of Odesa.

Moscow has said that Ukrainian power facilities are legitimate targets and such attacks are aimed at weakening Kyiv's military.

It says the latest strikes are retaliation for Ukrainian attacks that overshadowed the re-election of Russian President Vladimir Putin. (Reporting by Pavel Polityuk Editing by Tom Balmforth and David Goodman)