He recalled that US President Donald Trump had threatened to withdraw from the North Atlantic Alliance during his first term, but those threats were not carried out.
Stoltenberg said no one can say with certainty how likely such a scenario is, but urged taking such statements by the US leader seriously.
"It is not a law of nature that NATO will exist forever. NATO' survival in the next ten years is not set in stone," he told TV2, TASS reported.
According to him, US allies in NATO should focus not on Trump’s rhetoric but on their own actions. He called on them to take on greater responsibility for ensuring security and to increase defense spending if they want to preserve allied relations with Washington.
Earlier, Trump said that the United States will carefully re-examine its policy within NATO. "We pay trillions of dollars for NATO and they weren’t there for us," he claimed, referring to allies’ actions in the situation around the US-Israeli aggression against Iran.