The UN has failed to agree on a response to the use of chemical weapons in Syria's civil war.
"Whoever conducted the attacks, Russia ultimately bears responsibility for the victims in East Ghouta and countless other Syrians."US Secretary of State
France, the US and their allies want to press on with sanctions based on the findings of last year's expert inquiry, carried out in conjunction with the Organisation for the Prohibition of Chemical Weapons, which found that the Syrian government had used sarin and chlorine gas against its own people.
For its part Russia says the inquiry was biased and a "complete failure". It has proposed the establishment of a new alternative international investigative body to carry out the work. The US says this is an attempt to shield the Assad regime by means of distraction.
On two previous occasions, Russia has used its UN veto to block the extension of the previous inquiry.
Speaking at the UN, Nikki Haley, US Ambassador, said:
"Simply put when Russia doesn't like the facts they try and distract the conversation. That's because the facts come back over and over again to the truth Russia wants to hide: that the Assad regime continues to use chemical weapons against its own people."
Vasily Nebenzya, the Russian Ambassador to the UN retorted:
"Once again I reiterate why do you need an investigative mechanism? Even yesterday, and today prior to any investigation being conducted you are alleging without any doubts that this is something which was done by the Syrian government. So you are both judge and accuser."
The acrimonious session followed a meeting of world leaders convened by French Foreign Minister, Jean-Yves Le Drian in Paris earlier in the week, at which he launched a new International Partnership against Immunity for the Use of Chemical Weapons.
The meeting agreed to preserve evidence of chemical attacks from Syria and set out plans to prosecute the perpetrators.
Speaking at the conference, US Secretary of State Rex Tillerson said Russia bore ultimate responsibility.
"Whoever conducted the attacks, Russia ultimately bears responsibility for the victims in East Ghouta and countless other Syrians targeted with chemical weapons, since Russia became involved in Syria," he told reporters.
"There is simply no denying that Russia, by shielding its Syrian ally, has breached its commitments to the US as a framework guarantor. At a bare minimum, Russia must stop vetoing, or at the very least abstain, from future security council votes on this issue".
More than 130 chemical attacks were reported in Syria between 2012 and 2017, most of which have been informally attributed to the Assad regime.
The UN investigation found the Syrian government culpable in two specific cases, including a sarin attack on the opposition-held village of Khan Sheikhun in April last year, which left 80 people dead.
Last week a chlorine attack left 20 civilians struggling to breathe, most of them children.
So-called Islamic State has been blamed for some mustard gas attacks.
Jean-Yves Le Drian told the Paris meeting that, "faced by the recent banalisation of the proliferation and use of these odious arms, it is necessary to act. On this we will be judged by history."