(CNN) The official demise of a landmark arms control pact between the US and Russia is a "bad day" for stability in Europe, the military alliance's Secretary General Jens Stoltenberg told CNN Friday, hours after the US withdrew from the pact.
Speaking to CNN's Hala Gorani, the Norwegian politician called the end of the Intermediate-Range Nuclear Forces (INF) treaty with Moscow a "serious setback."
"I'm part of a political generation that was shaped during the 1980s, where we all were concerned for the risk of nuclear war and where we were actually able to reach the INF treaty that didn't only reduce the missiles but banned all intermediate range missiles and weapons," he said.
The Cold-War era pact was signed by US President Ronald Reagan and Soviet leader Mikhail Gorbachev in 1987. It has limited the development of ground-based missiles with a range of 500 to 5,500 kilometers, between both nations for the past three decades.
But the West says Russia has been violating the treaty since the days of the Obama administration. The Trump administration began taking steps this year to notify Russia and NATO that it would withdraw unless Moscow reversed course.
Stoltenberg said Russia had deployed new missiles that can reach European cities "within minutes," that are "hard to detect, are mobile and are nuclear capable, and therefore reduce the threshold of any potential use of nuclear weapons in an armed conflict."
That paired with the demised INF treaty made it a "bad day for all of us who believe in arms control and stability in Europe."
He, however, added that "NATO will take the necessary measures to protect our allies in a world without the INF treaty."
United States Secretary of State Mike Pompeo said Friday that "Russia is solely responsible" for the treaty's end.
It's a view Stoltenberg shares. "Today, the INF treaty ceases to exist because Russia has deployed the SSC-8 missile system," he told a news conference later on Friday.
"There are no new US missiles, no new NATO missiles in Europe but there are more and more Russian missiles," Stoltenberg told journalists.
Analysts now worry about a new Cold-War style arms race, something Stoltenberg is keen to avoid.
He told reporters Friday that NATO would respond to the risks posed by the Russian missiles in a "measured and responsible way."
"That is also the reason why we continue to work for arms control, non-proliferation, and disarmament."
This story has been updated to clarify the Secretary General's comments.