Russian Foreign Minister Sergey Lavrov said Monday that President Vladimir Putin had made clear talks with Ukraine are now impossible following the Ukrainian assault on Russia's Kursk Oblast.

"The president said it very clearly that following attacks, or even incursion, on the Kursk Region, any talks are impossible," Lavrov said, according to Russia's TASS news agency.

Ukrainian officials have suggested the purpose of the invasion of Kursk was to gain leverage for future negotiations with Russia, but Moscow's reaction to the incursion signals that the assault would only delay peace talks.

The Washington Post reported on Saturday that Russia and Ukraine were due to hold indirect negotiations in Qatar on a potential agreement to stop targeting each other's energy infrastructure, but it was derailed by the Kursk offensive.

Russian Foreign Ministry spokeswoman Maria Zakharova appeared to deny the Post report, saying Russia was not involved in any "direct or indirect" talks with Ukraine that could have been derailed by the Kursk offensive. Lavrov mentioned the report but only denied rumors that Russia and Ukraine had any "clandestine contacts" ahead of talks that were supposed to be brokered by Qatar.

Ahead of Ukraine's invasion of Kursk, Zelensky signaled he was open to holding peace talks with Russia, which was a significant shift in his position. He previously rejected the idea of diplomacy with Moscow unless Russia withdrew from the territory it had captured in Ukraine, as well as Crimea.