Concern after Peskov interview: could Russia use nuclear weapons? 1:26 (CNN) — The US military is constantly monitoring Russia’s nuclear arsenal as the war in Ukraine continues and Defense Secretary Lloyd Austin is being briefed two or three times a week by Army Gen. highest rank overseeing US nuclear weapons and defenses, according to multiple defense officials. The US has seen no indication that Russia has made any move to prepare nuclear weapons for use during the war, but two sources familiar with recent intelligence assessments told CNN that US officials are more concerned about the threat of for Russia to use them than at any time since the Cold War. The sources stressed, however, that it remains unlikely that Russian President Vladimir Putin would use any kind of nuclear weapon, with one source putting the chances of use at around 1%. Admiral Charles Richard, head of US Strategic Command, is providing Austin and other senior Pentagon leaders with a highly classified intelligence and operations update on the status of the Russian arsenal and any movement that may cause concern, according to the officials. defense. It includes information from the intelligence community that closely follows statements by Putin and other senior Russian leaders. Officials stressed that if any sudden developments occur between scheduled meetings, Austin and the Chairman of the Joint Chiefs of Staff, Gen. Mark Milley, will be briefed quickly before bringing the White House up to date. US Secretary of Defense Lloyd Austin(Credit: REUTERS/Sarah Silbiger) Monitoring any possible nuclear activity has always been a top priority for the Pentagon, but the urgency of the efforts increased shortly after Russia launched its invasion in February, when Putin put the country’s deterrent forces, including Moscow’s nuclear weapons, on the highest alert status. “We take note of what Mr. Putin said in the early days of this invasion. I think it’s also important to add that there hasn’t been any more of that rhetoric after that initial salvo in the early days, but yes, look, in light of what’s going on in Ukraine, and certainly in light of early rhetoric, we’re actively monitoring every day, and even today, and still today, the secretary is comfortable that we have a proper strategic deterrent posture in place , and there is no need to make any changes to it,” Pentagon press secretary John Kirby said Tuesday. On Tuesday, Russian Foreign Minister Sergei Lavrov refuted Ukrainian President Volodymyr Zelensky’s warning in an interview with CNN last week that Russia might be ready to use nuclear weapons in Ukraine, stressing that Russia has historically opposed the use of such weapons. Highly classified US military plans continue to be updated for what everyone considers an almost unthinkable scenario: the use of a nuclear weapon. The US military “has planned all of this,” a senior defense official said. “There is a range of things that Russia could do. We have all the scenarios of what Putin could do, the implications and the state of readiness” of both the Russian and US forces, they added. The official declined to give details. But American satellites and planes are constantly on the lookout for signs of Russian movements. Intelligence assets from both sides would be “able to see” if the other moved its nukes, the official said. The Biden administration has said publicly on multiple occasions that it sees no reason to change the alert status of the US arsenal. CNN previously reported that aircraft reconnaissance flights by the US have increased significantly. The information obtained on these flights is transmitted to the Strategic Command nuclear command and control network to form part of the overall nuclear intelligence assessment. Richard recently hinted at a House Armed Services Committee hearing that US readiness to respond to a Russian use of nuclear weapons is at an all-time high. “Right now, all I will say in open session is that the nation’s nuclear command and control is in a state of defense and resiliency the likes of which has never been seen in its history,” he told the panel. With information from Ellie Kaufman.