NATO follows with “great concern” reports from the Baltic Sea on leaks in the Russian Nord Stream gas pipelines, Secretary-General Jens Stoltenberg said on Tuesday.

Stoltenberg asserted that it is “extremely important to get all the facts on the table” and therefore NATO closely monitors the developments.

His remarks came after Swedish and Danish authorities confirmed that gas had been dripping from the pipelines under the Baltic Sea.

In his address to EU lawmakers, Stoltenberg also pointed out that “sham referenda” organized in four regions of Ukraine combined with mobilization and nuclear rhetoric is a “further escalation of the conflict” that will only lead to more death and more suffering.

He said the “use of any nuclear weapons is absolutely unacceptable.”

“Russia must know that the nuclear war cannot be won, must never be fought,” Stoltenberg said, adding that it is not highly possible that Moscow will actually deploy its nuclear arsenal.

Reiterating NATO’s support for Ukraine in the face of Russia’s “brutal war of aggression,” Stoltenberg underlined that NATO must continue to react.

Otherwise, “we are actually jeopardizing not only the security of Ukraine but also our own security” because Russian President Vladimir Putin or other leaders can conclude that “they get what they want” by using military force and violating international law, he added.