[1/2] CIA Director William Burns speaks during a House Intelligence Committee hearing on worldwide threats, in Washington, D.C., U.S., April 15, 2021.
Central Intelligence Agency Director William Burns warned Sergei Naryshkin, head of Russia's SVR foreign intelligence service, about the consequences of any use of nuclear weapons, a White House official said.
It was the first known high-level, face-to-face U.S.-Russian contact since Russia invaded Ukraine in February.
Zelenskiy said the CIA director had spent time in a bomb shelter before the two men met amid Russian missile strikes.
Putin has said Russia will defend its territory with all available means, including nuclear weapons, if attacked.