Earlier, White House spokesperson Kate Bedingfield said the US had information that Mr Putin "felt misled by the Russian military" and this had resulted in "persistent tension between Putin and his military leadership".

"Putin's war has been a strategic blunder that has left Russia weaker over the long term and increasingly isolated on the world stage," she said.

Pentagon spokesman John Kirby called the assessments "discomforting", because an uninformed Putin could result in a "less than faithful" effort at ending the conflict through peace negotiations.

"The other thing is, you don't know how a leader like that is going to react to getting bad news," he said.