The US has officially withdrawn from the INF Treaty, the landmark arms control agreement enacted to limit nuclear weapons, and accused Russia of deliberately violating the Cold War-era pact. The development came after Washington announced plans to test a new missile that would have been banned under the INF Treaty, a landmark deal that saw intermediate range nuclear projectiles dumped on the scrapheap, reducing the superpower rivalry. The US will not remain party to a treaty when other violate it. Russia bears sole responsibility,” Mike Pompeo, the Secretary of State declared on Twitter. “Russia’s noncompliance under the treaty jeopardises US supreme interests as Russia’s development and fielding a treaty-violating missile system represents a direct threat to the United States and our allies and partners,” he said in a separate statement. Nato chief Jens Stoltenberg insisted he did “not want a new arms race.” Mr Stoltenberg said all 29 Nato members stood behind the United States as he insisted Rusia was to blame. "Nato will respond in a measured and responsible way to the significant risks posed by the Russian 9M729 missile to Allied security," the alliance chief said. "We have agreed a balanced, coordinated and defensive package of measures to ensure Nato's deterrence and defence posture remains credible and effective," Mr Stoltenberg said. The treaty had banned the use of land-based missiles with a range of 500 to 5500 kilometres. The US had given six months to abide by the treaty and give verified evidence it had destroyed the non-compliant missile system, which it says Russia has not done. Washington accuses Moscow of developing, testing and field multiple battalions of the the SSC-8 or 9M729 ground-launched, intermediate-range cruise missile since at least the mid-2000’s. It says Russia has failed to act on its concerns, which it first raised in 2013. Defence expert Christian Molling, who warned “Europeans are very vulnerable,” said recently: “The key question now is whether the Americans and their European partners are deciding to upgrade conventionally or even nuclear to create opportunities to minimize the potential for Russian threats.” "Everyone is now afraid of an arms race, but it is important to note that Russia and Putin has been fanning its nuclear weapons arsenal well before the violation of the INF treaty; below the range of 500 kilometres on water and in the air," he told <em>Sueddeutsche Zeitung.</em> Europe is should be particularly concerned, he said, given its proximity. The missile Russia is believed to have developed could hit almost all European capitals. "Russia has caused the INF Treaty to collapse by secretly developing and deploying a treaty-violating missile system which can target Europe's capitals," UK Foreign Secretary Dominic Raab said on Twitter. "Their contempt for the rules-based international system threatens European security."