The Biden administration has generally decided to keep warnings about the consequences of a nuclear strike deliberately vague, so the Kremlin is worried about how Washington might react, the officials said, speaking on condition of anonymity to describe sensitive discussions. The White House’s effort to cultivate what is known in the world of nuclear deterrence as “strategic ambiguity” comes as Russia continues to escalate its rhetoric about the possible use of nuclear weapons amid domestic mobilization aimed at limiting Russian military losses in the eastern Ukraine. The State Department has tapped the private communications with Moscow, but officials have not said who delivered the messages or the scope of their content. It was unclear whether the United States had sent any new private messages in the hours since Russian President Vladimir Putin issued his latest veiled nuclear threat during a speech announcing a partial demobilization early Wednesday, but a senior U.S. official said the communication is done consistently. the last months. Putin faces anger in Russia over military mobilization and prisoner swap Dmitry Medvedev, deputy chairman of Russia’s Security Council, wrote on Thursday in a Telegram post that territories in eastern Ukraine would be “accepted to Russia” after the completion of organized “referendums” and promised to strengthen security in those areas. To defend this annexed land, Medvedev said, Russia is able to use not only its newly mobilized forces, but also “any Russian weapon, including strategic nuclear ones and those using new principles,” a reference to hypersonic weapons . “Russia has chosen its path,” Medvedev added. “There is no way back.” The comment came a day after Putin suggested that Russia annex occupied territories in southern and eastern Ukraine and formally incorporate the areas into what Moscow considers its territory. He said he was not bluffing when he promised to use all means at Russia’s disposal to defend the country’s territorial integrity – a veiled reference to the country’s nuclear arsenal. Biden administration officials stressed that this is not the first time the Russian leadership has threatened to use nuclear weapons since the start of the war on February 24, and said there is no indication that Russia is moving its nuclear weapons in preparation for an imminent strike. However, recent statements from the Russian leadership are more specific than previous comments and come as Russia is reeling from a US-backed Ukrainian counteroffensive. While the Kremlin’s earlier statements appeared to be aimed at warning the United States and its allies against going too far to help Ukraine, Putin’s latest comments suggest Russia is considering using a nuclear weapon on the battlefield in Ukraine to freeze gains and force Kyiv and its backers into submission, said Daryl Kimball, executive director of the Arms Control Association, a nonproliferation advocacy group in Washington. “What everyone needs to recognize is that this is one of the, if not the most, serious incidents where nuclear weapons might be used in decades,” Kimball said. “The consequences of even a so-called ‘limited nuclear war’ would be absolutely devastating.” US and Russian diplomats clash at UN over war in Ukraine For years, American nuclear experts have worried that Russia might use smaller tactical nuclear weapons, sometimes referred to as “nuclear battlefields,” to favorably end a conventional war on its terms — a strategy sometimes described as “escalation to de-escalation”. On Thursday, Vadym Skibitskyi, the deputy head of Ukraine’s military intelligence service, told the UK’s ITV News that it was possible Russia would use nuclear weapons against Ukraine “to stop our aggressive activity and destroy our state”. “This is a threat to other countries,” Skibitskyi said. “The detonation of a tactical nuclear weapon will have an impact not only on Ukraine but also on the Black Sea region.” The Ukrainians have tried to signal that even a Russian nuclear strike would not force them into capitulation — and in fact could have the opposite effect. “Nuclear threat… to Ukrainians?” Mykhailo Podolyak, an adviser to Ukrainian President Volodymyr Zelensky, tweeted on Wednesday. “Putin still doesn’t understand who he’s dealing with.” In an interview with CBS News’ “60 Minutes” that aired Sunday, Biden was asked what he would say to Putin if the Russian leader considered using nuclear weapons in the conflict against Ukraine. “Do not. Don’t do it. Don’t do it,” Biden said. “You will change the face of warfare unlike anything since World War II.” Biden declined to specify how the United States would respond, saying only that the response would be “coherent” and would depend “on the extent of what they do.” The Biden administration would face a crisis if Russia used a small nuclear weapon in Ukraine, which is not a US treaty ally. Any immediate U.S. military response against Russia would risk the possibility of a wider war between nuclear-armed superpowers — the avoidance of which the Biden administration has made its No. 1 priority throughout its Ukraine policymaking. Matthew Kroenig, a professor of government at Georgetown University and director of the Scowcroft Center for Strategy and Security at the Atlantic Council, has argued that the best option for the administration, if faced with a limited Russian nuclear strike on Ukraine, could be to step up support for Ukraine and conducts a limited conventional strike on the Russian forces or bases that launched the attack. “If it is Russian forces in Ukraine that launched the nuclear attack, the United States could strike those forces directly,” Kroenig said. “It would be calibrated to send a message that this is not a major war, but a limited strike. If you’re Putin, what do you do in response? I don’t think you’re saying immediately to drop all the nukes on the United States.” But even a limited US military conventional strike against Russia would be considered reckless by many in Washington, who would argue that they were not risking a full-scale war with a nuclear-armed Russia. James M. Acton, co-director of the nuclear policy program at the Carnegie Endowment for International Peace, said it makes no sense at this point to discount U.S. responses because there is such a wide range of possible Russian actions — from an underground nuclear test that harms no one in a large-scale explosion that kills tens of thousands of civilians — and there are no signs that Putin is close to crossing the threshold. “If he was really thinking very seriously about using nuclear weapons very directly, he almost certainly would want us to know,” Acton said. “He would rather threaten nuclear use and get us to make concessions than go down the path of nuclear use.” More than 1,300 arrests reported as Russians protest military mobilization US officials are stepping up efforts at the UN General Assembly this week to prevent Russia from seriously considering what would be the first use of a nuclear weapon in a conflict since the United States’ 1945 atomic bombing of Japan. Foreign Secretary Anthony Blinken, speaking at a UN Security Council meeting on Thursday, said Russia’s “reckless nuclear threats must stop immediately”. “This week, President Putin said that Russia would not hesitate to use, and I quote ‘all weapons systems available’ in response to a threat to its territorial integrity — a threat that is all the more threatening given the Russians’ intention to annex large areas of Ukraine in the coming days,” Blinken said. “When this is completed, we can expect President Putin to claim any attempt by Ukraine to liberate this land as an attack on so-called Russian territory.” Blinken noted that Russia in January joined other permanent members of the Security Council in signing a joint statement declaring that “nuclear war can never be won and must never be fought.” Hudson reported from the United Nations in New York.

War in Ukraine: What you need to know

The last: Russian President Vladimir Putin announced a “partial mobilization” of troops in an address to the nation on September 21, describing the move as an effort to defend Russian sovereignty against a West that seeks to use Ukraine as a tool to “divide and destroy Russia. .” Follow our live updates here. The battle: A successful Ukrainian counteroffensive forced a large Russian retreat in the northeastern region of Kharkiv in recent days, as troops abandoned towns and villages they had seized since the first days of the war and abandoned large amounts of military equipment. Annexation Referendums: Staggered referendums, which would be illegal under international law, are to be held from September 23 to 27 in the breakaway regions of Luhansk and Donetsk in eastern Ukraine, according to Russian news agencies. Another organized referendum will be held by the Moscow-appointed government in Kherson from Friday. Photos: Washington Post photographers have been on the ground since the start of the war — here are some of their strongest works. How you can help: Here are ways those in the US can help support the Ukrainian people as well as the donations people have made around the world. Read his full coverage Russia-Ukraine crisis. Are you on Telegram? Subscribe to our channel for updates and exclusive video.