Russians operations against Kyiv continue to struggle

 ISW:

The Russians have not yet abandoned their attacks on Kyiv, claims by Russian Defense Ministry officials notwithstanding. Russian forces continued fighting to hold their forwardmost positions on the eastern and western Kyiv outskirts even as badly damaged units withdrew to Russia from elsewhere on the Kyiv and Chernihiv axes. The Russian high command has likely concluded that it cannot seize Kyiv and may not be able to move artillery closer to the center of the city. It may have decided to stop its previous practices of forcing units that have already taken devastating losses to continue hopeless offensive operations and of feeding individual battalion tactical groups into the battle as they become available rather than concentrating them to achieve decisive effects. Russian officials are likely casting these decisions driven by military realities as overtures demonstrating Russia’s willingness to engage in serious ceasefire or peace negotiations, possibly to conceal the fact that they have accepted the failure of their efforts on the Kyiv axis.
...

The Russian advance in Mariupol continues to gain ground, and Russian forces have likely bisected or even trisected the city. Pockets of Ukrainian defenders continue to hold out in Mariupol, likely in several areas, but the Russians will likely complete the conquest of the city within days. Russian forces have likely taken significant casualties in the tough urban fighting in Mariupol, making it difficult to evaluate how much combat power the Russians will be able to harvest from Mariupol to use for further advances north and west.
...

Russia reportedly continues to struggle in its efforts to generate new combat power and replenish equipment. The Ukrainian General Staff reported on March 29 that Russian troops are drawing equipment out of long-term storage in Boguchar, Voronezh Oblast, but that 40% of that equipment is inoperable.[1] The General Staff also reported that Russian efforts to generate reinforcements from the Pacific Fleet could not produce even a single battalion because of refusals to fight.[2] We have no independent confirmation of these assessments, but Russian Defense Minister Sergei Shoigu‘s March 29 statement that Russia would not deploy conscripts to “hot spots” corroborates assessments of Russian soldiers’ unwillingness to enter the war.[3] The UK Ministry of Defense reported on March 28 that the Wagner Group is deploying forces, including senior leaders, to eastern Ukraine to make up for heavy Russian combat losses.[4]
...

Russian forces have likely abandoned efforts to encircle or seize Kyiv at this time, although they continue to fight to hold their current front lines on both banks of the Dnipro River. Multiple Ukrainian and Western reports indicate that some Russian forces are pulling back from the Kyiv axis.[5] Belarussian media showed videos of Russian forces moving back into Belarus from Ukraine on March 28 and March 29.[6] Russian forces continue to defend their current front-line trace, however, according to the Ukrainian General Staff and additional reporting below.[7] The Russians reportedly continued to bring artillery and missiles, including Iskander systems, toward the Ukrainian border in Belarus, presumably for use in the Kyiv and Chernihiv region.[8]
...

Mariupol appears to be the only place where Russians are even close to achieving their objectives and it has been one of the costliest battles of the war for both sides.  If Russia eventually defeats the Ukraine resistance in Mariupol they will mostly have a pile of rubble to rule over and making the city livable would be a major expense for Russia whose economy is already in shock from sanctions by the West and Japan. 

The Russian troops near Kyiv do not appear to have the combat force to even engage in a siege.  The Russian troops are having to dig in while they also have to fight Ukrainian counterattacks.  Those troops are also at the tail end of the Russian supply operations which appear to continue to be vulnerable to Ukraine attacks.

The Russians apparently did not engage in routine maintenance of their reserve equipment.  This can result in things like tires rotting and internal seals becoming unable to function making engines inoperable.  This will likely make it difficult for them to sustain current operations, much less increase their fighting ability without stepping up their manufacturing process which could take months at best.