I'm honestly not sure what Russia is thinking here (assuming there is any rational thought) - if the tactical maps some sites have come up with are correct as things stand Ukraine has a minimum of 40K soldiers from regular army and national guard type groups in the vicinity of Kyiv including at least 2 heavy armour brigades and mechanized infantry, 3+ artillery groups at brigade strength and 3 functional airbases with still functional AD. Without including the special forces, police, militia and volunteers, etc. while currently Russian forces in the region are less than 30K strong. With the total forces committed they can't hold both Ukraine and siege Kyiv while there is any non-negligible level of insurgency existing in the rest of the country and they still have to grind down the Ukrainian forces committed to the other regions which are heavier again in some cases like those deployed to the original line of control.
The only choices Russia has really is to commit a sizeable amount of their regular army, massive bombardments, pull out or if they can't cut off supplies from the West (which I assume they are wanting to utilise Belarus's forces for) lose very badly with Ukraine looking to press the advantage home.
