Mr. Blinken also criticized Russia for using the Zaporizhzhia nuclear plant as a staging ground for attacks on Ukrainian forces, saying the Ukrainians were unable to fire back out of concern they might strike a nuclear reactor or stored radioactive waste.
“That brings the notion of having a human shield to an entirely different and horrific level,” Mr. Blinken said.
The conference, which normally meets every five years, will be reviewing the three priorities of the treaty: preventing the spread of nuclear weapons, promoting and supporting peaceful nuclear energy and working toward global disarmament. But little concrete outcome is expected, given the current divisions among world powers.
Mr. Putin, who put his nuclear forces into “special combat readiness” in the early days of the invasion in February, also sent a message to the nonproliferation conference.
“We believe that there can be no winners in a nuclear war, and it must never be fought,” Mr. Putin wrote, according to Tass, the Russian news agency. “We advocate equal and inseparable security for all members of the international community.”