Russia cast a second veto in as many days at the United Nations Security Council on Friday to block the renewal of an international investigation to identify the perpetrators of chemical weapons attacks in Syria.
A Japanese-drafted resolution would have extended the UN-led Joint Investigative Mechanism (JIM) for 30 days to allow time for negotiations on a wider compromise.
But Russia used its veto power to prevent adoption after 12 council members voted in favor of the measure, effectively ending the mission. China abstained, while Bolivia voted no.
It was the 11th time that Russia has used its veto power to stop council action targeting its ally Syria.
"Russia is wasting our time," US Ambassador Nikki Haley told the council after the vote. "Russia has no interest in finding ground with the rest of this council to save the JIM."
"Russia will not agree to any mechanism that might shine a spotlight on the use of chemical weapons by its ally, the Syrian regime," she said. "It's as simple and shameful as that."
A resolution requires nine votes to be adopted at the council, but five countries -- Britain, China, France, Russia and the United States -- can block adoption with their veto power.
Japan put its proposal forward after Russia on Thursday and Oct. 24 vetoed US-drafted resolutions that would have allowed the expert investigators to continue their work for a year.
A separate Russian draft resolution that called for changes to the JIM failed to garner enough support.
"Any extension of the JIM's mandate for us is possible only provided fundamental flaws in its work are rectified," said Russian Ambassador Vassily Nebenzia.
The diplomat accused the JIM's leadership of having "disgraced itself with its fictitious investigation" of the sarin gas attack at the rebel-held town of Khan Sheikhoun in Idlib province.
He said that for the past two year the investigators had "rubber-stamped baseless accusations against Syria."
In a report last month, the JIM concluded that the Syrian air force had dropped the deadly nerve agent on Khan Sheikhoun, leaving scores dead.
After the veto, the council met behind closed doors at Sweden's request to hear another appeal for a temporary extension, but Russia again refused, diplomats said.
UN officials confirmed late Friday that the panel would end its work at midnight (0500 GMT Saturday) as there was no decision from the council to keep it in place.
The joint UN-Organization for the Prohibition of Chemical Weapons (OPCW) panel was set up by Russia and the United States in 2015 and unanimously endorsed by the council, which renewed its mandate last year.
Previous reports by the JIM have found that Syrian regime forces were responsible for chlorine attacks on three villages in 2014 and 2015, and that ISIS used mustard gas in 2015.