Russia has vetoed a US-drafted UN resolution that would have condemned last weekend's suspected gas attack near Damascus and established a new body to determine responsibility for Syrian chemical weapons attacks.
The vote on Tuesday afternoon in the 15-member Security Council was 12 in favour, Bolivia joining Russia in voting no, and China abstaining.
US Ambassador Nikki Haley said the US "went the extra mile" to get Russian support for the resolution to ensure that a new investigative body would be impartial, independent and professional - things she said would not be guaranteed by a rival Russian resolution.
Russia's UN Ambassador Vassily Nebenzia accused the United States of wanting the resolution to fail "to justify the use of force against Syria".
He said the resolution was trying to recreate the old expert body, whose extension Moscow blocked in November. He called that body "a puppet in the hands of anti-Damascus forces".
A Russian resolution that would have created a new expert body to determine responsibility for the chemical weapons attacks was also rejected.
The resolution needed at least nine yes votes in the 15-member council for approval but only six countries voted in favour. Seven council members, including the US, Britain and France, voted against the proposal and two abstained.
Ms Haley said the draft resolution was not impartial or independent since it would allow Russia to veto investigators and staff for the new body - and to block its findings.
She accused Russia of repeatedly shielding President Bashar Assad instead of working for Security Council unity.