The UK's top diplomat has said Russian forces must be pushed out of the "whole of Ukraine", adding "this is a time for courage, not for caution".
"We will keep going further and faster to push Russia out of the whole Ukraine," said UK Foreign Secretary Liz Truss on Wednesday in a speech in London. "We need to apply this tough stance."
Truss vowed the UK would "double down" on its support for Ukraine and "prepare for the long-haul", warning that "if Putin succeeds there will be untold further misery across Europe".
"We can't be complacent," she said. "The fate of Ukraine hangs in the balance."
Truss's statement at the annual foreign policy speech is the clearest expression of the UK's war aims, marking a toughening of her country's stance towards Russia.
It suggests that Russian forces must leave areas of Ukraine they occupied in 2014, such as Crimea, alongside territory captured since the start of the invasion in February.
Many Western leaders have avoided voicing such demands, fearing it might provoke Russia.
Truss's comments come at a time of rising geopolitical tensions between Russia and the UK, with Moscow warning on Tuesday of a "response" if the UK continues to "provoke" Ukraine to attack Russia.
At yesterday's speech, Truss called on Western allies to send "heavy weapons, tanks, airplanes" to Ukraine and cut off Russian oil and gas imports "once and for all".
"There must be no way for Putin to fund this appalling war," she said.
Truss called on countries to take a more proactive policy towards the Ukraine war, claiming "the world should have done more to deter the invasion.
"We will never make that same mistake again."
She continued: "Some argue that we should not provide heavy weapons for fear of causing something worse.
Read more on euronews.com