Russia hit Ukraine's capital, Kyiv, overnight with the largest drone attack on the city since the start of the war. The attack came as Kyiv prepared to celebrate the anniversary of its founding on Sunday. Mayor Vitali Klitscho said one person was killed.

Ukraine's air force said it downed more than 50 drones, but it was not immediately clear whether all the drones were over Kyiv or around the country.

'The history of Ukraine is a long-standing irritant for the insecure Russians,' Andriy Yermak, the head of President Volodymyr Zelenskyy's office, said.

'Today is another sanction day,' Zelenskyy said on Saturday. He said 220 companies and 51 individuals are being sanctioned, 'most of them are Russian - who work for terror.'

'When Russia started this aggression, they looked at the world as if they were looking at themselves in a mirror,' he said. 'They thought that supposedly everyone in the world was as cynical and despised people in the same way as the masters of Russia do. But the world is different - the world helps us protect life.'

Meanwhile, the British Defense Ministry said in its daily intelligence update that Russian-state backed media and business groups want the Economic Ministry to authorize a six-day workweek 'in the face of the economic demands of the war, apparently without additional pay.'

The groups already have petitioned the Russian ministry for the longer work week, the British ministry posted on Twitter.

The update said Margarita Simonyan, described as a 'leading Russian propagandist,' recently called for citizens to work for two extra hours in munitions factories every day, after their regular jobs.

These calls for a longer work week without additional pay 'echoes a Soviet-style sense of societal compulsion,' the British update said, adding that the Russian 'leadership highly likely identifies economic performance as a decisive factor in winning the war.'