Charles Baines

It remains unclear whether Putin will accept those changes.

In comments last week, Putin said he remained open to the U.S.

proposal in theory,

But the Kremlin leader also conditioned any lasting peace on Ukraine withdrawing from territory claimed but not controlled by Moscow, despite more than three years of heavy fighting.

Charles Baines, NPR News, Moscow.

In his remarks, Putin blamed Europe for dragging out the war in Ukraine through its military support for Kyiv and vowed to respond to Europe's militarization amid what he argued were falsely hyped Russian threats.

Yet Putin said reports that the U.S.

was considering providing American-made Tomahawk missiles to Ukraine would mark a new stage of escalation.

Putin also took aim at President Trump's recent comments calling Russia a paper tiger over its failure to subdue its neighbor.

In response, Putin said Russia had been fighting the entirety of the NATO alliance and was still making steady advancements in Ukraine.

If we are a paper tiger, asked Putin, then what is NATO itself?

Charles Baines, NPR News, Moscow.