President Joe Biden again is warning Russian President Vladimir Putin against using weapons of mass destruction (WMDs) in Ukraine.
"Don't. Don't. Don't. You will change the face of war unlike anything since World War II," he said in an interview with CBS News scheduled to air Sunday night.
Biden would not comment specifically on a U.S. response if Russia were to use chemical or nuclear weapons in Ukraine.
'They'll become more of a pariah in the world than they ever have been," he added. "And depending on the extent of what they do will determine what response would occur.'
It was not Biden's first warning to Putin: Following a meeting with European Union and G-7 partners and NATO allies in March, Biden said NATO would respond "in kind" to any use of WMDs in Ukraine.
"We will respond if he uses it," Biden said, referring to Putin. "The nature of the response depends on the nature of the use."
A month later, Biden chastised Russian Foreign Minister Sergey Lavrov as "irresponsible" after Lavrov told Russian state television that the risks of nuclear war were "considerable."
"No one should be making idle comments about the use of nuclear weapons or the possibility of the need to use them," Biden said.
FILE - Russia's President Vladimir Putin (5th L) visits the National Defense Control Center (NDCC) to oversee the test of the new Russian hypersonic missile system Avangard, capable of nuclear and conventional warheads, in Moscow, Dec. 26, 2018.
Just days into his invasion of Ukraine, Putin ordered Russia's nuclear forces on high alert for the first time since the fall of the former Soviet Union, prompting the White House to assemble a team of national security officials - the so-called Tiger Team - to study potential responses in the event Russia deployed chemical, biological or nuclear weapons against Ukraine, neighboring nations or NATO convoys of weapons and aid headed for Ukraine.
In 2000, Russia updated its military doctrine to allow the first use of nuclear weapons in 'in response to large-scale aggression utilizing conventional weapons in situations critical to the national security of the Russian Federation," according to the U.S.-based Arms Control Association. The 1997 version of the doctrine had allowed the first use of nuclear arms only 'in case of a threat to the existence of the Russian Federation."
The newest version also states for the first time that Russia has the right to use nuclear weapons to respond to all 'weapons of mass destruction' attacks.
Meanwhile, Russia's targeting of the Zaporizhzhia nuclear plant has renewed nuclear anxiety across Europe. International Atomic Energy Agency (IAEA) Director General Rafael Mariano Grossi reported Saturday that the plant, Europe's largest, is once again receiving electricity from the national grid.
Grossi cautioned that the general situation for the plant, however, remains precarious, as long as Russian forces are shelling in the wider region around Zaporizhzhia.
The nuclear plant remains under Russian control, the IAEA said, but Ukrainians are handling its operations.