- Video report by ITV News Correspondent Juliet Bremner
Russia and Britain clashed at an emergency meeting of the UN Security Council, called after the US launched strikes in Syria after a chemical weapons attack.
The UK's ambassador said Bashar al-Assad had been "put on notice", and claimed that Moscow was humiliated by its failure to rein in the Syrian dictator.
The Russian Federation in turn accused Britain of "colonial hypocrisy" and "lies" as it warned against becoming involved militarily in the Arab country.
Russia's UN representative Vladimir Safronkov said: "Stop putting forward these unprofessional arguments and accusations against my country. These are not diplomatic. These are lies.
"Don't even try to get into fights in the Arab world. Nothing will work and nothing will be achieved.
"All Arab countries recall your colonial hypocrisy."
Matthew Rycroft, the UK's ambassador to the UN, said that Russia had given Assad "everything he could have dreamed of" by supporting him in spite of his using chemical weapons against civilians.
He said: "The greatest war criminal of all, Bashar Assad, has now been put on notice.
"The US strike was a proportionate response to unspeakable acts that gave rise to overwhelming humanitarian distress."
"Russia sits here today humiliated by its failure to bring to heel a puppet dictator entirely propped up by Russia, Hezbollah and Iran," he added.