During a visit to Ukraine’s capital Kiev, the Foreign Secretary said the UK stood “shoulder to shoulder” with the country in the face of Russian aggression.
But she warned international leaders that the military threat on Ukraine’s border was a “litmus test” for Western allies.
After talks with the country’s foreign minister Dmytro Kuleba, she said: “The free world needs to draw the line under a decade of drift. If we hang back, that would only embolden the bullies in their campaign against sovereignty and the right of self-determination.
Disregard “This is a litmus test for the West. We must stand up to and defuse Russian aggression now, because if we don’t it will embolden not only the Kremlin, but aggressors, authoritarians and autocrats everywhere.
“What matters here in Eastern Europe matters for the world and it matters for the future. We have a duty to ensure that the next 10 years are better than the last.”
Later she condemned a call from the Duma – Russia’s parliament – for its president Vladimir Putin to recognise two regions of Ukraine – Donetsk and Luhansk – as “independent”.
She said: “The Duma’s request shows flagrant disregard for Russia’s commitments under the Minsk agreements. If this request were accepted, it would represent a further attack on Ukraine’s sovereignty and territorial integrity, signal an end to the Minsk process and demonstrate a decision to choose a path of confrontation over dialogue.
“We urge Russia to end its pattern of destabilising behaviour against Ukraine and to implement the commitments it has freely signed up to, including the Minsk agreements.”
Ms Truss also warned the West needed to “wise up” in relation to how it deals with Russia.
She said: “For years now, Russia has been building its capabilities, violating its commitments and probing our weaknesses.
“The West needs to wise up. We need to work together to discredit their arguments in public.”
The Foreign Secretary said blocking the Nord Stream 2 gas pipeline from Russia and imposing sanctions must be on the table because “in dangerous times, we have to take a hardheaded approach”.
Western allies have to accept the economic “pain” of facing Russia down, Ms Truss insisted.
During the talks she said the UK would be increasing funding for Ukraine democracy and energy independence by £12million to £100million.
