“They arrange constant provocations with shelling of the territory of the nuclear power plant and try to bring their additional forces in this direction to blackmail our state and the entire free world,” Mr. Zelensky said in an address late Saturday evening.

“Every Russian soldier who either shoots at the plant, or shoots under the cover of the plant, must understand that he is becoming a special target for our intelligence, for our secret service, for our army,” he said.

Russian officials say that Ukrainian forces are shelling the plant, and Moscow has repeatedly warned of the danger of a major nuclear incident.

The United Nations’ nuclear regulator, the International Atomic Energy Agency, has lobbied for months to negotiate safe passage to inspect the plant, which is still being operated by Ukrainian workers.