Washington - Russia is "paranoid" about being challenged by Nato and its efforts to rival American power could push it into a new Cold War, the head of US intelligence said on Tuesday.
"They're greatly concerned about being contained," the director of national intelligence, James Clapper, told the Senate Armed Services Committee.
Clapper said that Russia fears the installation of a missile defence network in Europe could negate the threat posed to the West by its nuclear arsenal.
"I think the Russians fundamentally are paranoid about - about Nato," he said.
"So, a lot of these aggressive things that the Russians are doing, for a number of reasons - great power status, to create the image of being co-equal with the United States - I think could probably, could possibly go on, and we could be into another Cold War-like spiral here," he added.
Relations between Moscow and Washington are at a low point, amid disputes over Nato's expansion in eastern Europe and Russia's military interventions in Syria and Ukraine.