Ukrainian President Volodymyr Zelenskiy said he doesn't think Vladimir Putin is bluffing when he says Moscow would be ready to use nuclear weapons to defend Russia.
The Russian president said in a televised address last week that Moscow would use "all available means" to protect Russia and its people if its territorial integrity were threatened.
"Look, maybe yesterday it was bluff. Now, it could be a reality," Zelenskiy, who had previously played down such warnings as nuclear blackmail, told CBS News on Sunday.
"I don't think he's bluffing," Zelenskiy added.
The Ukrainian president said Russian strikes on or near two Ukrainian nuclear plants could be considered "contemporary use of nuclear weapons or nuclear blackmail".
Kyiv accuses Moscow of repeatedly shelling the Russian-occupied Zaporizhzhia nuclear power plant during the war in Ukraine, and more recently conducting a missile strike near the Pivdennoukrainska nuclear plant.
Moscow denies shelling the Zaporizhzhia plant, accusing Kyiv of being responsible. It did not comment on the Pivdennoukrainska strike.
North Korea fired a short-range ballistic missile on Thursday towards the sea off the peninsula's eastern coast, South Korea's military said, the first such launch in more than 40 days after a series of weapons tests earlier this year.
A wildfire prompted an evacuation alert on Wednesday about 30 km (18.64 miles) from Vancouver, one of Canada's largest metropolitan areas, as blazes in Western Canada continued to spread due to dry and hot weather.
Israel said two of its soldiers were killed in southern Lebanon on Wednesday while Lebanese authorities said Israeli retaliatory attacks killed at least one person, a flare-up in violence that coincided with the latest round of talks between the two countries.
Italy took the unprecedented step of placing all its major cities on the highest level of health alert due to high temperatures on Thursday while Hungary turned off the lights at some of its best-known buildings to save energy as a heatwave maintained its grip on large parts of Europe.
Rescuers worked on Thursday to douse fires and clear debris in Ukraine's eastern city of Balakliia after Russian strikes on homes killed three overnight, authorities said on the Telegram messaging app.