Kazakhstan's president described floods across the north of the country as a national disaster on Tuesday and ordered his government to free up funds for relief efforts by cutting spending elsewhere.

In Russia, also hit by the worst floods in living memory, a top ally of President Vladimir Putin said regional authorities had fallen short in their forecasting and emergency response.

Water levels in rivers in swathes of Russia's Ural and southwestern Siberian regions, as well as adjacent areas of Kazakhstan, were still rapidly rising, officials said.