Speaking in a rare public appearance, Mr Burns addressed fears of “bloody” attrition warfare by claiming Putin is overestimating his abilities in this area, just as he overestimated that his army could take Kyiv in a matter of days.
He also quipped that the Russian President was “probably too healthy” and was not suffering with cancer as some news outlets have reported.
The CIA director admitted that this was an “informal intelligence judgement”, having worked with Putin for more than two decades as the US ambassador to Moscow.
While speaking at Aspen in Colorado Mr Burns warned that future Chinese aggression in Taiwan was a growing risk, despite President Xi Jinping being “unsettled” with Putin’s lack of progress in Ukraine.
He said: “I would not underestimate President Xi’s determination to assert the People’s Republic of China’s control over Taiwan.
“I think he is determined that his military has the capability to undertake such an action should he decide to move in that direction [in terms of using military force].
“I think the risk of that becomes higher, it seems to us, the further into this decade that you get.”
He claimed that Beijing was looking to learn from Moscow’s mistakes in their approach to Taiwan.
Mr Burns added: “I think our sense is it [the lessons from Russia’s war] probably affects less the question of whether the Chinese leadership might choose force down the road to control Taiwan, but how and when they would do it.
READ MORE: Ukraine: Putin rocked as unit ‘destroyed’ by Zelensky’s forces
The CIA director also shared the US military’s latest estimates for the number of Russian casualties since the invasion began.
He said it stood at around 15,000 Russian dead and some three-times that number wounded.
The Ukrainian toll is thought to be relatively steep – “probably a little less” than the Russian figures.