Nuclear disarmament talks between Russia and the United States scheduled to take place in Egypt on Tuesday were cancelled last minute on Monday, according to the Russian Foreign Ministry and the United States Embassy in Moscow.The two nuclear superpowers were set to sit down in Cairo to commence the Strategic Arms Reduction Talks (START), in what would have represented the first talks under the nuclear treaty since the Russian invasion of Ukraine.Moscow announced that the talks, which had already been suspended for two years due to the Covid-19 pandemic, would be postponed again without offering any formal reason."Russia unilaterally postponed the meeting and said it would offer new dates," Russian news outlet Kommersant cited the United States embassy in Moscow as saying, effectively blaming Moscow for the fresh delay.The parties were expected to use the talks to establish a framework allowing both sides to carry out inspections of their counterparts' nuclear arsenal after Russia ceased allowing United States inspections in August.The START treaty, which was last renewed in 2011, caps the number of strategic nuclear warheads that the United States and Russia can deploy.The postponement of this months talks comes as relations between the two countries are at their lowest ebb since the Cold War, with Russian President Vladimir Putin repeatedly making veiled threats to use the nuclear option as his countrys bungled invasion of Ukraine enters its 10th month.Had the meeting gone ahead, Tuesdays talks could have signaled a new readiness from both sides to return to the negotiating table, amid high tensions caused by the Kremlin invasion of Ukraine and Washingtons subsequent donation of billions of dollars of military aid to Kyiv.