Russia and China have vetoed a United Nations resolution to refer the situation in Syria to the International Criminal Court for possible prosecution of war crimes and crimes against humanity committed during the country's civil war.
The move on Thursday was the fourth time Russia and China had blocked UN Security Council action on Syria. Moscow is a close ally of the Syrian president, Bashar al-Assad.
The US ambassador to the UN, Samantha Power, accused the Russians of providing diplomatic protection to the Syrian government "no matter what it does".
British Foreign Secretary William Hague said he was appalled by the Russian and Chinese veto.
In a statement published after the vote he said the countries would have to justify "why they are continuing to shield those responsible for the most horrific atrocities," the Reuters news agency reported.
Dozens of countries backed the French-drafted resolution in a move to demand a path to justice in the conflict, which has entered its fourth year.
Prior to the vote, Russia's ambassador to the UN, Vitaly Churkin, told reporters that his country's vote would be "boringly predictable" and dismissed the resolution as a "publicity stunt".
Speaking after the vote, Churkin said his country shared the "emotions" of the countries who supported the bill but questioned whether France was using the bill as a pretext for armed intervention.
Al Jazeera's James Bays, reporting from the UN in New York, said Western nations could pursue special tribunals independent from the UN to bring individuals in Syria to justice.
The resolution would have referred Syria's crisis to the world's permanent war crimes tribunal in The Hague without targeting either the government or the opposition.
Before the vote, UN Deputy Secretary-General Jan Eliasson pleaded with council members to find unity and "put an end to this long nightmare", the AP news agency reported.
More than 150,000 people have been killed during the Syrian conflict.