NEW YORK, Sept 21 (Reuters) – President Vladimir Putin will not win the war in Ukraine despite his order to mobilize thousands of additional troops, NATO’s secretary general said on Wednesday, calling the Russian leader’s threat to use nuclear weapons ” dangerous and reckless rhetoric.” Jens Stoltenberg told Reuters in an interview that Russia’s first mobilization since World War II would escalate the conflict and cost more lives, but the move was proof that Putin had miscalculated since the February 24 invasion of Ukraine . In a speech to Russians earlier, Putin announced he would call up 300,000 reservists to fight in Ukraine and backed a plan to annex parts of the country, hinting to the West that he was prepared to use nuclear weapons to defend Russia. read more Sign up now for FREE unlimited access to Reuters.comSign up “If the territorial integrity of our country is threatened, we will use all available means to protect our people – this is not a bluff,” Putin said. Russia has “many weapons to respond,” Putin added. Stoltenberg, speaking to Reuters editor-in-chief Alessandra Galloni in New York, said the 30-nation Western defense alliance would remain calm and “not engage in this kind of reckless and dangerous nuclear rhetoric with President Putin.” “President Putin’s speech shows that the war is not going according to President Putin’s plans. He made a big miscalculation,” Stoltenberg said. NATO Secretary General Jens Stoltenberg speaks during a press conference at a NATO summit in Madrid, Spain, June 30, 2022. REUTERS/Violeta Santos Moura read more “More troops will escalate the conflict. That will mean more suffering, more loss of life – Ukrainian lives, but also Russian lives,” Stoltenberg added. Putin’s speech followed mounting casualties and battlefield setbacks for Russian forces, which have been driven from areas they seized in northeastern Ukraine in a Ukrainian counteroffensive this month and bogged down in the south. Stoltenberg said that although Russian troops were poorly equipped and lacked proper command and control, it was difficult to see the conflict ending in the short term as long as Russia does not accept that Ukraine is a sovereign, independent nation. “The only way to end this war is to prove that President Putin is not going to win on the battlefield. When he realizes that, he needs to sit down and negotiate a reasonable deal with Ukraine,” said Stoltenberg, the former prime minister of Norway. Stoltenberg added that alliance members have provided unprecedented support to Ukraine and that NATO allies must now replenish their stockpiles of weapons and ammunition. As NATO prepared for the “long haul” in dealing with Putin, it was now in close dialogue with the defense industry to restore its stockpile of hardware, Stoltenberg said. Stoltenberg said China is among the security challenges facing NATO, but he does not see China as an adversary. Stoltenberg also noted China’s “coercive behavior” in the South China Sea and against its neighbors as well as “the way they violate basic human rights.” Sign up now for FREE unlimited access to Reuters.comSign up Reporting by Humeyra Pamuk in New York and John Chalmers in Brussels. Written by John Chalmers. Editor: Will Dunham Our Standards: The Thomson Reuters Trust Principles.