Russia's war in Ukraine has had a "corrosive" effect on Russian President Vladimir Putin, CIA Director William Burns said Saturday, with discontent over the conflict creating a "once-in-a generation opportunity" for the spy agency.

Speaking at the Ditchley Foundation in the UK, Burns called Putin's invasion of Ukraine "the most immediate and acute geopolitical challenge to international order today."

The address came one week after the head of Wagner mercenary group Yevgeny Prigozhin led his forces in a brief mutiny against Russia's military command.

In doing so, he accused Russia of targeting his forces with deadly missile strikes in Ukraine and launched broadsides against Moscow's narrative of the conflict: saying it was started "for the self-promotion of a bunch of bastards" and that Russia's troops were retreating in Ukraine's east and south.

"The impact of those words and those actions will play out for some time, a vivid reminder of the corrosive effect of Putin's war on his own society and his own regime," Burns said.

He called the war a "strategic failure" for Moscow that has exposed military weaknesses, hurt the economy and spurred a bigger and stronger NATO.

"Disaffection with the war will continue to gnaw away at the Russian leadership ... That disaffection creates a once-in-a-generation opportunity for us at CIA," he said.

"We're not letting it go to waste," he added, noting the CIA recently posted on Telegram to let Russians know how to reach the CIA via the dark web.

"We had 2.5 million views in the first week, and we're very much open for business."

Burns did not mention a recent trip to Ukraine where he met with intelligence counterparts and President Volodymyr Zelensky. The visit took place before Prigozhin's insurrection.

In his speech the spy chief also focused on China, which he called "the only country with both the intent to reshape the international order and, increasingly, the economic, diplomatic, military and technological power to do so."

Burns warned of Chinese President Xi Jinping's "growing repression at home and his aggressiveness abroad" and said the CIA has established a mission center focused exclusively on the Asian power and more than doubled the percentage of overall budget on China activities.