Reports suggest Ukrainian president has informed Washington he will sack army chief
Rumours of his imminent sacking have been circulating and usually refer to apparent disagreements between the two men.
Washington has made no comment, saying it is a matter for Ukraine and not the US.
Meanwhile, on Friday night air sirens sounded throughout south-eastern Ukraine as groups of Russian drones were reported heading towards the cities of Kryvi Rih, Kherson, Dnipro, and Odesa.
The Kyiv Independent newspaper reported on the attack on Kryvi Rih.
Meanwhile Russian social media reported that there were multiple explosions in Russia's Voronezh region.
The Voronezh regional authorities claimed there had been one drone attack during the night.
Governor Alexander Gusev claimed that the drone was shot down and that there were no casualties.
And Ukrainian media shared a video of what it said was a suspected drone attack on the Lukoil refinery in Volgograd, the largest oil refinery in Russia's Southern Federal District.