Russian forces are apparently intensifying attacks on Ukrainian cities, killing at least 12 people, including children, in the eastern city of Dnipro.

A senior official with the Ukrainian forces said a Russian missile struck a nine-story residential building in Dnipro on Saturday, leaving at least 12 dead and more than 60 others wounded.

Russian strikes were also confirmed in the capital, Kyiv, and the western city of Lviv.

Ukrainian President Volodymyr Zelenskyy called for more military assistance from other countries. In a video message released on Saturday, the president says his country needs the "weapons in the warehouses of our partners" to stop Russian terror.

Meanwhile, the Russian newspaper Kommersant reported on Friday that the country's presidential election will take place in March next year as scheduled. It also said President Vladimir Putin's close aides have started preparations for Putin to seek re-election.

The paper said officials in the Putin administration had recently held preliminary talks with experts on the campaign, citing a source close to the administration.

Putin has yet to disclose whether he will run in the next election. Attention is now focused on whether he will seek a fifth term amid Russia's ongoing invasion of Ukraine.