“It’s going to bleed over,” McMaster, who served as former President Donald Trump’s National Security adviser, said during an appearance on CBS Mornings. “If you think about what [Russian President Vladimir] Putin has done in recent years, he’s enabled the serial episodes of mass homicide in the Syrian civil war.”

McMaster continued, “this shouldn’t surprise us in terms of Russia’s brutality and we have to not assume that this catastrophe that we’re seeing is going to remain contained within Ukraine or really even in the Black Sea region, or Europe.”

The comments by McMaster come as fighting continues to take place between Russian and Ukrainian military forces in several different Ukrainian cities.

On Thursday, Ukraine said that Russian troops had attacked the Zaporizhzhia nuclear power plant, which is the largest power plant in Europe, causing a fire to ignite. Ukrainian President Volodymyr Zelensky warned that if the nuclear power plant was destroyed, it would cause “the end of Europe.”

However, the International Atomic Energy Agency (IAEA) said in a statement that they were informed by Ukraine that despite Russian forces taking control of the power plant, it “continued to be operated by its regular staff and there had been no release of radioactive material.”

“Ukrainian counterparts informed the IAEA that a projectile overnight had hit a training building in the vicinity of one of the plant’s reactor units, causing a localized fire that was later extinguished,” the IAEA said. “The safety systems of the plant’s six reactors had not been affected and there has been no release of radioactive material.”

During a press conference on Friday, North Atlantic Treaty Organization (NATO) Secretary General Jens Stoltenberg said the attack at Zaporizhzhia “demonstrates the recklessness of this war and the importance of ending it.”

While Russian forces have not made any moves to extend its efforts past Ukraine and into other European nations, Stoltenberg noted on Friday that the alliance “will continue to do what it takes to protect and defend every inch of NATO territory,” after the NATO Response Force was deployed for the first time in history.

U.S. Secretary of State Antony Blinken made similar comments, saying on Friday that “We seek no conflict. But if conflict comes to us we are ready for it and we will defend every inch of NATO territory.”

Amid the ongoing fighting, several different Ukrainian officials and some U.S. lawmakers have called for a no-fly zone to be imposed over Ukraine. Despite these calls, both the U.S. Department of Defense and NATO have said that they do not plan to impose the defense strategy.