President Joe Biden on Friday called the leaks in the Nord Stream pipelines a “deliberate act of sabotage” and accused Russia and President Vladimir Putin of “pumping out disinformation and lies,” though he did not directly accuse Moscow for the leaks. Biden’s strong words mark the first time he’s directly asserted that the leaks were a result of sabotage, pushing back on Russia’s narrative about the incident amid Moscow’s escalating efforts to assert its claim over Ukrainian territory. On Monday, leaks were discovered in the pipelines, prompting investigations by European authorities that determined powerful underwater explosions had occurred just before the pipelines burst in several places. Biden said that the United States is working with allies to “get to the bottom of exactly – precisely what happened” with the leaks and that he has already directed resources to help allies enhance protection of the pipelines, which funnel gas from Russia into the European Union. “Let me say this, it was a deliberate act of sabotage and now the Russians are pumping out disinformation and lies,” Biden said. At “the appropriate moment when things calm down, we’re gonna send the divers down to find out exactly what happened,” he added. “We don’t know that yet.” Western nations have said leaks in Nord Stream 1 and 2, two Russian gas pipelines, are likely the result of sabotage. But up to this point, US officials had been largely circumspect compared to their European counterparts in drawing conclusions about the leaks. Putin on Friday claimed “Anglo-Saxons” were to blame for the explosions, claiming: “Well, for the Anglo-Saxons sanctions are no longer enough, they switched to sabotage. Unbelievable, but it is a fact.” Biden, however, insisted that what Putin is saying about the leaks is “not true.” And national security adviser Jake Sullivan said Friday that the US does not believe any NATO ally is behind the leaks. The pipelines were controversial long before Russia waged war on Ukraine, largely because of fears around European reliance on Russian energy. If Russia did deliberately cause the explosions, it would be effectively sabotaging its own pipelines: Russian state company Gazprom is the majority shareholder in Nord Stream 1 and the sole owner of Nord Stream 2. But officials familiar with the latest intelligence say that Moscow would likely view such a step as worth the price if it helped raise the costs of supporting Ukraine for Europe. US and western intelligence officials believe Putin is gambling that as electricity costs rise and winter approaches, European publics could turn against the Western strategy of isolating Russia economically. Sabotaging the pipelines could “show what Russia is capable of,” one US official previously told CNN. Allegations about the leaks come amid what the West has cast as Moscow’s most serious escalation in the war in Ukraine since Russia’s invasion began in February. Last week, Putin announced partial mobilization in Russia, calling up 300,000 reservists. And earlier Friday, Putin delivered a formal speech announcing that Russia is to annex nearly a fifth of Ukraine following so-called referendums, which have universally been dismissed as shams by Ukraine and Western countries. Biden on Friday responded to Putin’s earlier remarks about annexation, saying, “America is fully prepared with our NATO allies to defend every single inch of NATO territory. Every single inch. So, Mr. Putin, don’t misunderstand what I’m saying. Every inch.” Biden asserted that Western allies “are not going to be intimidated by Putin and his reckless words and threats. He’s not going to scare us or intimidate us. Putin’s actions are a sign he’s struggling.” “The sham referenda he carried out and … the sham routine that he put on this morning … well, the United States is never going to recognize this and quite frankly, the world’s not going to recognize it, either. He can’t seize his neighbor’s territory and get away with it. It’s as simple as that,” he continued. Earlier Friday, the US announced new sanctions in response to Putin’s annexation announcement. The measures include a combination of export controls, visa restrictions and asset freezes, as part of an effort to further clamp down on Russian supply chains – and the individuals directing the efforts – critical to maintaining the war effort. The United States, Biden said during his remarks, “is going to continue to stay the course” with Ukraine. “We’re going to continue to provide military equipment so that Ukraine can defend itself and its territory and its freedom, including additional resources that the Congress is going to give me today of $13 billion more dollars to help Ukrainians defend themselves and fight back,” he continued. This story has been updated with additional developments Friday.