Russia's foreign minister accused his British counterpart of being deaf at a rancorous meeting in Moscow that showed how far apart the two nations are on the current crisis in Ukraine.
"I'm honestly disappointed that what we have is a conversation between a dumb and a deaf person...Our most detailed explanations fell on unprepared soil," Sergei Lavrov told a joint news conference stood next to Liz Truss.
"They say Russia is waiting until the ground freezes like a stone so its tanks can easily cross into Ukrainian territory.
"I think the ground was like that today with our British colleagues, from which numerous facts that we produced bounced off."
Watch: Russian foreign secretary says Liz Truss meeting ‘like talking to a deaf person’
The extraordinary language used by Lavrov showed how strained relations between Russia and the UK are, with today's meeting only making things worse.
In response to Lavrov, Truss said: “I was not mute in our discussions earlier, I put forward the UK’s point of view on the current situation and the fact that as well as seeking to deter Russia from an invasion into Ukraine, we are also very resolute in pursuing the diplomatic path.”
Russia and Britain have had dire relations for years, hitting low points with the fatal 2006 poisoning of former Russian security officer Alexander Litvinenko in London and the attempted killing of former Russian double agent Sergei Skripal and his daughter with a nerve agent in Salisbury in 2018.
Truss challenged Lavrov directly over his assertion that Russia is not threatening anyone with its build-up of troops and weaponry near Ukraine's borders.
"I can't see any other reason for having 100,000 troops stationed on the border, apart from to threaten Ukraine. And if Russia is serious about diplomacy, they need to remove those troops and desist from the threats," she said.
Russia has presented the West with a series of demands to guarantee its security, complaining it feels threatened by repeated waves of NATO enlargement and the refusal of the alliance to rule out membership for its neighbour Ukraine, a fellow former Soviet republic.
"No one is undermining Russia's security - that is simply not true," Truss said, adding that it was "perfectly proper" for Ukraine to defend itself and seek alliances.
When discussing the poisonings on British soil Lavrov said London had never presented any facts to support its accusations of Russian involvement in both cases, or in the attempted poisoning of Kremlin critic Alexei Navalny in 2020.
He said Truss had not varied her tone throughout their two-hour meeting, and had ignored his explanations while repeating statements and demands that Britain had made before.
The government has been attempting to show a clear display of force and solidarity with Ukraine amid the build-up of Russian troops on their border.
On Thursday Prime Minister Boris Johnson held talks with the head of NATO in Brussels and his Polish counterpart Mateusz Morawiecki in Warsaw.
Speaking in Brussels he said: “This is probably the most dangerous moment in the course of the next few days in what is the biggest security crisis Europe has faced for decades."
Later Johnson said he was in Poland “showing our solidarity with our NATO partners and fortifying NATO’s eastern frontier”.
He added the military support for Poland was to show we stand “shoulder to shoulder with our allies” but also to demonstrate NATO’s commitment to its eastern members as a whole.
“It’s partly to show that we stand shoulder to shoulder with our allies in Poland, which we always do, but also to show that the West as a whole will strengthen NATO's eastern frontiers, rather than the reverse.
“(Vladimir) Putin, the Kremlin, should understand that if they want less NATO on their western borders, as it were, this is entirely the wrong way to go about it.”
Johnson's strong words were undermined by former prime minister Sir John Major criticism of the Partygate scandal on Thursday.
Sir John said ministers had regularly been sent to “defend the indefensible”, making the government look “distinctly shifty”, as he suggested MPs have a “duty” to act to restore trust in politics.
Johnson hit back saying it was “demonstrably untrue” that allegations of lockdown parties in No 10 had “shredded” Britain’s diplomatic reputation.