Exclusive: NATO chief calls Putin's Ukraine escalation 'dangerous and reckless' - Reuters

NEW YORK, Sept 21 (Reuters) - President Vladimir Putin's thinly veiled threat to use nuclear weapons after Russian setbacks in Ukraine was "dangerous and reckless rhetoric," NATO's secretary general said on Wednesday, adding that the only way to end the war was to prove Moscow will not win on the battlefield.

But, the NATO chief added, it also represented evidence that Putin had made a "big mistake" with Russia's decision to invade its neighbor on Feb.

Stoltenberg, speaking to Reuters Editor in Chief Alessandra Galloni in New York on the margins of the annual United Nations General Assembly meetings, said the 30-nation Western defense alliance will stay calm and "not engage in that same kind of reckless and dangerous nuclear rhetoric as President Putin.".

"The speech of President Putin demonstrates that the war is not going according to President Putin's plans," Stoltenberg said.

"He made a big mistake, strategic mistake," Stoltenberg said of Putin, while making a grim prediction.

That will mean more suffering, more loss of lives - Ukrainian lives, but also Russian lives," Stoltenberg said.

Putin said, offering no evidence, that officials in NATO member states had threatened to use nuclear weapons against Russia, and that Russia "also has various means of destruction.".

NATO has not seen any change in Russia's nuclear posture and readiness, Stoltenberg said, but added that the key was to prevent such an escalation.

As NATO was prepared for a "long haul" in dealing with Putin, it was now in close dialogue with the defense industry to build back its stocks of weapons and ammunition, Stoltenberg said.

Russian President Vladimir Putin announced a "partial mobilisation" on Wednesday that will see 300,000 Russian reservists called up in a significant escalation of Russia's war in Ukraine.