NATO declared on Tuesday it would go ahead with its annual routine nuclear deterrent exercises as a fresh barrage of Russian missiles rained down on Ukrainian cities.

Russia accuses West of 'nuclear rhetoric'

NATO will go ahead with its annual routine nuclear deterrent exercises as cancelling it now would send the wrong signal to Moscow, NATO head Jens Stoltenberg told a news conference on Tuesday in Brussels.

And the military strength of the alliance was the best way to prevent any escalation of tensions with Russia, he added.

Also on Tuesday, Russian Deputy Foreign Minister Sergei Ryabkov said in an interview posted on the ministry's website that the West was attempting to escalate the situation through "nuclear rhetoric" and a possibility of Russia using weapons of mass destruction.

"A direct clash with the United States and NATO is not in Russia's interests," he said, warning the West of a dangerous situation that uncontrolled escalation could lead to.

Kremlin spokesman Dmitry Peskov said on Wednesday that Russia deplores "every day that Western heads of state, the U.S. as well as European, practice nuclear rhetoric every day."

This came in response to a question about U.S. President Joe Biden's interview by CNN.

Asked by CNN anchor Jake Tapper how realistic he believed it would be for Putin to use a tactical nuclear weapon, Biden responded: "Well, I don't think he will."

Massive strikes continue 

Russia has continued its massive strikes on Ukrainian energy and military command facilities, which started on Monday, the Russian Defense Ministry said Tuesday.

Monday's attacks killed 23 people and wounded 100 others in Ukraine, including 7 deaths and 49 injuries in the Kyiv city, Deputy Head of Ukraine's Presidential Office Kyrylo Tymoshenko said Tuesday on Telegram.

About 30 percent of Ukraine's energy infrastructure were hit in Russia's missile attacks on Monday and Tuesday, Ukraine's Energy Minister Herman Halushchenko told CNN in an interview.

ZNPP loses off-site power

The restored power line supplying the Russian-controlled Zaporizhzhia Nuclear Power Plant (ZNPP) in Ukraine has been cut again, forcing the plant to switch to emergency diesel generators, said Rafael Grossi on Wednesday, director general of the International Atomic Energy Agency (IAEA), in his tweet, describing it as "a deeply worrying development."

Accusing the Russian forces controlling the facility of refusing to allow it to refuel the generators, Ukraine's state nuclear energy company Energoatom confirmed in a statement that "the plant was down to generate power, which it blamed on a rocket attack on a nearby substation."

External power at the plant was restored later on Wednesday. 

"I've been informed by our team on site that external power to #Zaporizhzhya NPP is restored," Grossi said on Twitter.

(With input from agencies)