Ukrainian President Volodymyr Zelenskyy gave an urgent plea for intervention after officials said Russian troops shelled Ukraine's largest nuclear power plant overnight.
"Russia wants to repeat Chernobyl, but six times worse," Zelenskyy said in a video message. "Europe wake up, tell your politicians: 'Russian troops are shelling a nuclear power plant in Ukraine. Zaporizhzhya nuclear power plant.'"
The president warned there are six power units at the Zaporizhzhia nuclear power plant -- where a fire ignited during the shelling -- and only one power unit exploded at the Chernobyl nuclear power plant, the site of the 1986 nuclear disaster.
"The Russian military must be stopped immediately," Zelenskyy said. "Shout to your politicians. Ukraine has 15 nuclear units. If there is an explosion, it is the end of everything. The end of Europe. This is the evacuation of Europe. Only immediate action by Europe can stop Russian troops. Prevent the death of Europe from the catastrophe at the nuclear power plant."
President Joe Biden spoke with Zelenskyy to receive an update on the fire at the power plant and "joined President Zelenskyy in urging Russia to cease its military activities in the area and allow firefighters and emergency responders to access the site," the White House said in a readout of the call.
British Prime Minister Boris Johnson also spoke to Zelenskyy about the "gravely concerning situation" at the power station and said he would be seeking an emergency U.N. Security Council meeting "in the coming hours," his office said.
A White House official told ABC News its latest information shows no indications of elevated levels of radiation.
The International Atomic Energy Agency, the United Nations nuclear watchdog group, also tweeted that Ukraine's regulatory authority said there hasn't been any change in radiation levels reported at the site in the wake of the blasts.
-ABC News' Uliana Lototska and Molly Nagle