KYIV, Ukraine — A top Kyiv military official said that more than 400 fallout shelters were being readied in the capital and that similar measures were being taken elsewhere around the country to prepare for a possible nuclear attack from Russia.
“I am preparing for the worst-case scenario, but I hope everything will be fine,” the official, Oleksiy Kuleba, the head of the Kyiv regional military administration, told Hromadske, a Ukrainian news outlet, in an interview published on Tuesday.
The authorities are designating 425 shelters for use in a nuclear emergency and are outfitting them with necessary supplies, he said. Evacuation routes are being updated in cities, towns and villages. All emergency workers are receiving protective gear and training. And the authorities are developing communication methods to warn the public if an attack is imminent, including via government hotlines, loudspeakers and radio broadcasts.
“In particular, there will be cars with loudspeakers that will inform the public,” Mr. Kuleba said.
Worries that the Kremlin might turn to its nuclear arsenal as it suffers setbacks on the battlefield have deepened since President Vladimir V. Putin of Russia, in a speech in September, raised the specter of using such weapons to hold on to Moscow’s slipping territorial gains.
And on Wednesday, Russia’s defense minister, Sergei K. Shoigu, repeated unfounded claims that Ukraine was trying to make a “dirty bomb.” Such accusations, made during a meeting with the joint board of the military departments of Belarus and Russia, echoed previous ones by Russian officials that Western officials have dismissed, suggesting that Moscow could be trying to create a pretext for launching its own attack.
Senior U.S. officials have expressed concern about the possibility of Mr. Putin deploying tactical nuclear weapons, which carry lower yields and are meant to be used at shorter ranges than the warheads carried on intercontinental ballistic missiles.
The New York Times reported on Wednesday that senior Russian military leaders recently had conversations to discuss when and how Moscow might use a tactical nuclear weapon in Ukraine, contributing to heightened concern in Washington and allied capitals, according to multiple senior American officials.
While American officials say they see no evidence that the Russians were moving nuclear weapons into place or taking other tactical measures to prepare for a strike — and many top Ukrainian officials have said the threats amount to a form of nuclear blackmail — local and state authorities across Ukraine are taking steps to educate the public and prepare.
In the event of a nuclear attack, Mr. Kuleba said, the first priority is finding shelter.
Residents of Kyiv have become familiar with where their local shelters are, with more than 1,000 registered bunkers spread across the Kyiv region, he said. But many are simple basements, some with windows facing the streets, that are not suitable for protection from nuclear fallout. The 425 special shelters are deeper underground, more fortified and well-ventilated.
The next priority, he said, is communication.
“It is likely that if a nuclear strike takes place, there will be no phone service,” Mr. Kuleba said. “The only thing that will keep working is the radio.”
All of the designated shelters will be outfitted with portable battery-powered radios in the next two weeks, he said.
All emergency services in the Kyiv region have been issued equipment that protects from radiation, Mr. Kuleba said, and emergency medical workers have completed training in the past week about how to respond in the event of a nuclear attack.
The risk of nuclear fallout can feel very real in Ukraine, a country that still bears the scars of the Chernobyl accident in 1986, one of the worst nuclear disasters in history. Chernobyl is only about 60 miles north of Kyiv.