ministry of defence
The army has a "lack of experienced and credible" commanders working on its Ukraine invasion, according to the MoD.
UK intelligence suggests Russian officials will also be "distracted" as they try to avoid "culpability" for the invasion's failures.
Missiles have hit Lviv in Ukraine's west while the besieged eastern city of Mariupol is holding out.
The Pentagon says Putin has achieved "exactly zero" of his objectives inside Ukraine.
The ministry of defence's update followed Russia's promise to withdraw in two major regions of Ukraine.
"I don’t think you can trust what is coming out of the mouth of Putin’s war machine,” Dominic Raab said.
Western officials are concerned Russia might use unguided aerial "dumb bombs" that could easily miss their targets and hit civilians.
The UK's ministry of defence believes Russian troops have made "minimal progress" in recent days.
The ministry of defence has provided a scathing analysis of the performance of Putin's troops on the frontline.
“You cannot go and fight if you’re in the British Army," Grant Shapps said.