Russia on Wednesday vetoed a UN resolution demanding the Syrian regime cooperate with an investigation into a deadly chemical attack last week.
Britain, France and the United States had put forward the measure in response to the sarin gas attack in the rebel-held town of Khan Shaykhun on April 4 that left 87 dead, including 31 children.
Moscow blocked the UN Security Council action against its ally for an eighth time.
The Russian veto came after US Secretary of State Rex Tillerson declared following talks in Moscow that there was a "low level of trust" between the US and Russia.
China, another veto-holding power at the council, abstained in the vote, as did Kazakhstan and Ethiopia.
Bolivia voted against the measure and 10 other council members supported it.
"With its veto, Russia said 'no' to accountability, Russia said 'no' to cooperation with the UN's independent investigation and Russia said 'no' to a resolution that would have helped to promote peace in Syria," said US Ambassador Nikki Haley.
"The international community has spoken. Russia now has a lot to prove," she said.
TRT World’s Lorna Shaddick reports from New York.
Russian Deputy Ambassador Vladimir Safronkov recalled that Moscow had "consistently expressed our categorical disagreement" with the draft resolution, but that Western governments had insisted on a vote.
The proposed resolution would have condemned the attack and expressed the council's full backing to investigators from the Organization for the Prohibition of Chemical Weapons (OPCW).
The draft would have demanded that the Syrian regime provide flight plans, flight logs and other information on its military operations on April 4, hand over the names of commanders of any aircraft and provide access to air bases to UN investigators.
The West has accused Assad's forces of carrying out the attack in Idlib province that shocked the world.
France and Britain expressed its dismay over the Russian veto.
"This puts Russia on the wrong side of the argument," British Foreign Secretary Boris Johnson said in a statement in London.
In Paris, French President Francois Hollande said, "Russia bears a heavy responsibility" by systematically opposing multilateral action to protect its Syrian ally Assad.
Time to end brutal war
US President Donald Trump told allies on Wednesday it was time to end Syria's "brutal" civil war.
Trump branded the regime leader Bashar al Assad a "butcher" and questioned Russia's role in the chemical attack.
Trump, standing alongside NATO Secretary General Jens Stoltenberg, called on allies to "work together to resolve the disaster" in Syria and thanked them for condemning Assad.
"Vicious slaughter of innocent civilians with chemical weapons including the barbaric killing of small and helpless children and babies must be forcefully rejected by any nation that values human life," Trump told reporters.
That's a butcher. That's a butcher. So I felt we had to do something about it. I have absolutely no doubt we did the right thing, and it was very, very successfully done.
"It is time to end this brutal civil war, defeat terrorists and allow refugees to return home."