The UK and US have become increasingly worried that Russia will invade after the Russian president stationed about 100,000 troops on Ukraine’s border.
US secretary of state Antony Blinken arrived in Switzerland this morning for talks with the Kremlin’s foreign minister Sergei Lavrov at the Hotel President Wilson in Geneva.
Mr Blinken and his deputies have been meeting with European leaders this week to gather support among allies to commit to hitting Russia with sanctions if it goes ahead with an attack.
President Putin has issued a series of demands to the West, including that Ukraine — which Moscow sees as its backyard — be stopped from joining Nato.
Russia previously seized and annexed the Crimean peninsula in southern Ukraine in 2014.
She urged Mr Putin to “desist and step back before he makes a massive strategic mistake”.
Speaking to the Australian thinktank the Lowy Institute in Sydney, Ms Truss said the Government is ready to “put very severe sanctions in place” and British forces are working to support Ukraine’s defensive capabilities.
Ms Truss, along with defence secretary Ben Wallace, are in Australia to discuss the next stage of Aukus, a defence partnership which brings together Australia, the US and the UK.
Ms Truss said The Kremlin “has not learned the lessons of history” and an “invasion will only lead to a terrible quagmire and loss of life, as we know from the Soviet-Afghan war and conflict in Chechnya.”
She called on the “free world” to reduce its economic dependence on Russia as the tensions continue.
When asked by the Australian thinktank’s executive director Michael Fullilove why she was confident the “free world would stand its ground” against Russia, she replied: “I think it’s very important to note the commitments that Russia made in the 1994 Budapest Agreement in exchange for Ukraine giving up its nuclear weapons.”
She added: “Russia agreed alongside the UK and US to protect Ukraine‘s sovereignty and territorial integrity.
“So the claims that are being made by Vladimir Putin are completely wrong about what has happened but it is true that the free world has not been doing enough since the end of the Cold War to make sure that we are deterring aggressors.”
Britain is supplying Ukraine with anti-tank missiles for self-defence and around 100 training soldiers.
Russia has denied any invasion plans and accused Western democracies of aggression.
Ms Truss added: “If there is an incursion by Russia into Ukraine, it would come at a massive cost.
“We are prepared to put very severe sanctions in place, we are also working to support Ukraine in terms of defensive capability, what I would say as well is that dealing with this immediate situation is of course an absolute priority.
“But the free world also needs to work together to reduce economic dependence on Russia to put in place the agreements that help countries have alternatives in terms of trade and investment.”