NATO nations will not impose a no-fly zone over Ukraine, despite pleas from some in Ukraine.

Secretary Jens Stoltenberg called it a "painful decision," saying that NATO has a responsibility not to escalate the conflict by engaging Russian forces directly in Ukraine, either on the ground or in the air.

Enforcing a no-fly zone would involve NATO planes in Ukraine potentially shooting down Russian planes, Stoltenberg said Friday. President Biden's administration has likewise ruled out such a move, saying it is "not going to happen."

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"We understand the desperation, but we also believe that if we did that, would end up with something that could end in a full-fledged war in Europe involving many more countries and causing much more human suffering," he said.

NATO Secretary Jens Stoltenberg took questions from reporters Friday, March 4, 2022.

NATO Secretary Jens Stoltenberg took questions from reporters Friday, March 4, 2022. (NATO)

Ukraine President Volodymyr Zelenskyy said this week that the West should consider a no-fly zone, and Ukrainian member of Parliament Lesia Vasylenko said Friday that a no-fly zone is "the only thing we need right NOW."

The war in Ukraine will likely be "worse" in the coming days, "with more death, more suffering, and more destruction, as the Russian armed forces bring in heavier weaponry and continue their attacks across the country," Stoltenberg said.

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NATO is strengthening its ties with non-member nations Finland and Sweden, Stoltenberg said. He condemned the Russian attack on a nuclear power plant in Ukraine, calling it "reckless."

This image made from a video released by Zaporizhzhia nuclear power plant shows bright flaring object landing in grounds of the nuclear plant in Enerhodar, Ukraine Friday, March 4, 2022. (Zaporizhzhia nuclear power plant via AP)

This image made from a video released by Zaporizhzhia nuclear power plant shows bright flaring object landing in grounds of the nuclear plant in Enerhodar, Ukraine Friday, March 4, 2022. Russian forces shelled Europe’s largest nuclear plant early Friday, sparking a fire as they pressed their attack on a crucial energy-producing Ukrainian city and gained ground in their bid to cut off the country from the sea. (Zaporizhzhia nuclear power plant via AP)

The head of the International Atomic Energy Administration said that no radiation was released in the attack, and that a fire at the plant was extinguished.