Russia vetoed a US-drafted resolution on setting up a panel to identify the perpetrators of toxic gas attacks after chemical weapons were allegedly used in the rebel-held town of Douma.
It was the 12th time that Russia has used its veto power at the council to block action targeting its Syrian ally.
The council voted two more times on draft texts put forward by Russia, but both measures failed to garner the nine votes required for adoption, laying bare divisions at the top UN body over Syria.
As the showdown between Russia and the United States got underway, Moscow's Ambassador Vassily Nebenzia accused the United States of "planting this resolution" as a "pretext" to justify action against Syria and "taking yet one more step toward confrontation."
"We are using the veto in order to protect international rule of law, peace and security, to make sure that you do not drag the Security Council into your adventures," Nebenzia said.
President Donald Trump has warned that there will be a "big price to pay" for the alleged use of toxic gas in Douma that killed at least 40 people, according to Syrian medics and rescuers.
After the second Russian measure was defeated, Nebenzia addressed US Ambassador Nikki Haley directly, appealing to the United States to refrain from military action.
"I would once again ask you, once again beseech you to refrain from the plans that you are currently developing for Syria," he said.
Protecting a monster
Haley said Russia was to blame for the council's failure to take action on Syria, now in its eighth year of war.
"Russia has trashed the credibility of the council," she said.
"History will record that, on this day, Russia chose protecting a monster over the lives of the Syrian people."
Russia had proposed setting up an investigative panel under rules that would have required Security Council approval of its findings -- a measure the West charged would compromise its independence.
A second defeated Moscow-drafted resolution would have offered backing for the fact-finding mission of the Organisation for the Prohibition of Chemical Weapons (OPCW) to Syria, but would not identify the perpetrators of attacks.
Twelve of the 15 council members backed the US-drafted measure. Bolivia voted against it alongside Russia, while China abstained.
The two Russian draft resolutions won six and five votes respectively.
A draft resolution requires nine votes to be adopted in the 15-member council and no veto from the five permanent members - Britain, China, France, Russia and the United States.
Russia and Syria have called for the OPCW to send its experts to Douma, where toxic gas was allegedly used in an attack on Saturday that killed dozens.
The OPCW has said the team of experts will deploy to Syria shortly.
The US proposal would have revived the work of a previous panel, known as the Joint Investigative Mechanism, that shut down in November when Russian vetoed the renewal of its mandate.
That panel had found that the Syrian air force had dropped sarin on the village of Khan Sheikhun in April of last year.
