<p>Russia faces Western sanctions "heavier than anything" seen before if it invades Ukraine, British Prime Minister Boris Johnson said on Tuesday after allied leaders held crisis talks on Moscow's threats.</p>.<p>Johnson again warned Russian President Vladimir Putin of the likely devastation from any incursion by his forces, as he updated parliament following the call late Monday with the US and European allies.</p>.<p>"We agreed that we would respond to any Russian attack on Ukraine in unison by imposing coordinated and severe economic sanctions, heavier than anything we've done before against Russia," he said.</p>.<p>Asked if Moscow could be frozen out of the global Swift system for financial payments, Johnson said: "There is no doubt that that would be a very potent weapon."</p>.<p>He noted that such a step would have to be handled by the United States, as the centre of the global financial system, adding: "We're in discussions about that."</p>.<p>Ukrainians would be "dogged and tenacious" in resisting any Russian incursion, Johnson said, after authorising the deployment of some 2,000 British anti-tank weapons to Kyiv along with military trainers.</p>.<p>"The ensuing bloodshed would be "comparable to the first war in Chechnya, or Bosnia, or any other conflict that Europe has endured since 1945", the prime minister said.</p>.<p>"We cannot bargain away the vision of a Europe whole and free" that arose after the end of the Cold War in 1989, "because Russia has placed a gun to Ukraine's head", he added.</p>.<p>But Johnson said sending NATO combat troops to Ukraine, which is not part of the military alliance, was "not a likely prospect in the near term".</p>.<p><strong>Watch the latest DH videos:</strong></p>
<p>Russia faces Western sanctions "heavier than anything" seen before if it invades Ukraine, British Prime Minister Boris Johnson said on Tuesday after allied leaders held crisis talks on Moscow's threats.</p>.<p>Johnson again warned Russian President Vladimir Putin of the likely devastation from any incursion by his forces, as he updated parliament following the call late Monday with the US and European allies.</p>.<p>"We agreed that we would respond to any Russian attack on Ukraine in unison by imposing coordinated and severe economic sanctions, heavier than anything we've done before against Russia," he said.</p>.<p>Asked if Moscow could be frozen out of the global Swift system for financial payments, Johnson said: "There is no doubt that that would be a very potent weapon."</p>.<p>He noted that such a step would have to be handled by the United States, as the centre of the global financial system, adding: "We're in discussions about that."</p>.<p>Ukrainians would be "dogged and tenacious" in resisting any Russian incursion, Johnson said, after authorising the deployment of some 2,000 British anti-tank weapons to Kyiv along with military trainers.</p>.<p>"The ensuing bloodshed would be "comparable to the first war in Chechnya, or Bosnia, or any other conflict that Europe has endured since 1945", the prime minister said.</p>.<p>"We cannot bargain away the vision of a Europe whole and free" that arose after the end of the Cold War in 1989, "because Russia has placed a gun to Ukraine's head", he added.</p>.<p>But Johnson said sending NATO combat troops to Ukraine, which is not part of the military alliance, was "not a likely prospect in the near term".</p>.<p><strong>Watch the latest DH videos:</strong></p>