The director of the CIA believes that Russian President Vladimir Putin is “not serious about negotiations at this stage” of the war in Ukraine and that “Ukraine’s progress on the battlefield is likely to shape the prospects for diplomacy” to end the current conflict. This was announced by Bill Burns on Tuesday, CNN reports.

Speaking publicly for the first time since classified US military documents surfaced online, Burns emphasized the importance of the planned offensive in Ukraine, saying “there is a lot at stake in the coming months.”

“Instead of backing down, he doubled down,” Burns said of Putin, adding that the Russian president believes he can polish Ukraine and the West.

The director of the CIA separately noted that Ukraine continues to defend Donbas, which, according to one of the released intelligence documents, is likely to reach a dead end.

“Russia’s attrition campaign in the Donbass is likely to reach a dead end, hindering Moscow’s goal of conquering the entire region by 2023,” one of the classified documents says.

“Real countries are fighting back,” Burns said Tuesday, adding that Ukraine and its president have done just that.

“Putin was deeply wrong” in his assumptions about Ukraine before the war, Burns added.

Burns stressed the importance of continued U.S. support for Ukraine, including through intelligence sharing, at a time when the leak of classified documents raises questions about the administration’s view of the conflict.

Burns said that the CIA does not see “significant changes in the deployment of nuclear weapons by the Russian leadership.”

He also said that the leak of classified military documents is an urgent problem for the US that is “as intense as any other” at the moment.

Burns, while stressing the importance of balancing short-term and long-term issues, specifically pointed to leaks as an immediate problem facing US intelligence agencies.

The CIA director said the Justice Department is currently investigating the leak and declined to elaborate on his understanding of the matter.

Burns made the remarks Tuesday at Rice University, where he discusses Russia’s invasion of Ukraine, China’s aggressive posture, Iran’s nuclear enrichment and other pressing foreign policy issues at the school’s Baker Institute for Public Policy, according to the school’s website.