Tempers boiled over at the United Nations on Wednesday (12 April) when a Russian envoy launched into a tirade against a British ambassador over events in Syria, at one point saying furiously: "Look at me while I'm talking to you."
Vladimir Safronkov, Russia's deputy ambassador to the UN, appeared to lose his cool while responding to the UK's UN ambassador Matthew Rycroft, who accused the Kremlin of supporting the "murderous" Assad regime.
Jabbing his finger towards Rycroft, at the UN Security Council session in New York, an angered Safronkov said: "You are afraid. You have been losing sleep over the fact that we might be working together with the United States.
"That is what you fear. You're doing everything to make sure that this kind of cooperation be undermined. Look at me when I'm speaking. Don't look away. Why are you looking away?"
Accusing Rycroft of having behaved "irresponsibly, offensively, and obscenely" in his criticism of Russia and other states, he concluded angrily: "Don't you dare insult Russia again."
The resolution was presented by the US, UK and France, who were angered by Russia blocking the move.
The US accused Russia of protecting a "murderous regime", with Secretary of State Rex Tillerson saying relations between the US and Russia had reached a low point.
Boris Johnson, the UK foreign secretary, said he was also "dismayed" by the Russian veto, saying Moscow was "on the wrong side of the argument".
The chemical incident on rebel-held Khan Sheikhoun, on 4 April, killed more than 80 people.
British scientists who took samples from the site concluded that nerve gas sarin, or a sarin-like substance, had been used.
Western allies blamed Bashar al-Assad's Syrian government for launching the alleged chemical attack, with US President Donald Trump ordering missile strikes against a Syrian air force base in response.
But the Syrian government denies it was responsible, with Russia's Vladimir Putin also rejecting the allegations, saying Syria had given up its chemical stockpile.
Russia has called for an independent international investigation, and questioned how Western countries could have assigned responsibility to the Syrian regime so quickly.
It has blamed the chemical incident on Syrian rebels, saying they possessed a stockpile of chemical weapons that were hit by a conventional airstrike.
The proposed UN resolution – which Russia said had an "anti-Syrian slant" – would have backed international investigators to probe the details of the chemical incident.
It would have allowed them access to "any sites deemed relevant", such as Syria's air bases, and access to information such as flight plans, logs and the names of military personnel in command of any aircraft being probed.
A previous attempt at a compromise resolution which left out the request for flight logs had been dismissed by the US, UK and France.
It is the eighth time during Syria's six-year-old civil war that Russia has used its UN Security Council veto to protect ally Assad.
Addressing the UN Security Council session on 12 April, Rycroft said: "Time and time again, Russia has abused its veto protect the regime and to defend its use of chemical weapons.
"What has Russia got in return for its seven vetos in six years? Russia's initiative in 2013 to dismantle Syria's chemical weapons has been exposed as a shambles.
"Russian pride in the Astana process has been turned to humiliation and Russia's credibility and reputation across the world have been poisoned by its toxic association with Assad.
"They have chosen to side with a murderous, barbaric criminal rather than with their international peers. They have chosen the wrong side of history.
"However, it is not to late for Russia to change course, not to late for Russia to use its influence over the regime to bring conflict to an end."
US Ambassador to the United Nations, Nikki Haley, also called on Moscow to stop protecting Assad, saying the US would work with Russia towards a political solution for Syria.
"Russia once again has chosen to side with Assad, even as the rest of the world, including the Arab world, overwhelmingly comes together to condemn this murderous regime," Haley told the 15-member Security Council.
"If the regime is innocent, as Russia claims, the information requested in this resolution would have vindicated them."