Russia vetoed Tuesday a US-drafted resolution that would have extended by a year an investigation of who is behind chemical weapons attacks in Syria.

It was the ninth time Russia has used its veto power at the Security Council to block action targeting its Syrian ally.

Russia opposed renewing the mandate of the joint UN-Organisation for the Prohibition of Chemical Weapons (OPCW) panel before it releases a report on a sarin gas attack in Khan Sheikhun expected on Thursday.

Britain, France and the United States have accused President Bashar al-Assad's forces of carrying out the April 4 attack on the opposition-held village, killing scores of people, including children.

After Russia cast its veto, US Ambassador Nikki Haley said Moscow was "once again" siding "with the dictators and terrorists who use these weapons."

"Russia has once again demonstrated it will do whatever it takes to ensure the barbaric Assad regime never faces consequences for its continued use of chemicals as weapons," Haley said in a statement.

China and Kazakhstan abstained from the vote, Bolivia joined Russia in voting against and 11 other countries backed extending the mandate.

The panel, known as the Joint Investigative Mechanism (JIM), was set up by Russia and the United States in 2015 to identify the perpetrators of chemical attacks in Syria's six-year war.

Its mandate was renewed last year by the council, which must decide on a further renewal by November 17.

- Dishonoring Russia -

Russia failed at the opening of the meeting to garner enough support for a motion to delay the vote until next month. 

Russian Ambassador Vassily Nebenzia said the veto did not mean that the investigation was shut down. He added that Moscow would seek to amend the panel's mandate to ensure it is impartial.

"We did not close the JIM. We simply did not take a decision on extending it today," he said. "We will return to it."

Britain, France and the United States agreed that another vote could be held in the coming weeks to allow the JIM to continue its work.

Nebenzia accused the United States and its partners of seeking a vote on the measure "to show up and dishonor Russia."

"What is taking place today is not very pleasant," said Nebenzia. "It stinks, in fact."

"We are seeing a well-rehearsed spectacle, which only strives to show up and embarrass one country," he added.

In a statement released in Moscow, the Russian foreign ministry insisted that it had the right to study the upcoming report before making an assessment and accused the United States of trying to "impose its position."

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.

- Who is to blame for Khan Sheikhun? -

More than 87 people died in the nerve gas attack in Khan Sheikhun that drew global outrage and prompted the United States to fire cruise missiles at a Syrian air base from which the West says the assault was launched.

Last month, UN war crimes investigators said they had evidence that the Syrian air force was behind the attack, despite repeated denials from Damascus.

Russia maintains that the sarin attack was most likely caused by a bomb set off directly on the ground, not by a Syrian air strike as alleged by the West.

While the OPCW has established that sarin was used in the April attack, it does not have a mandate to assign blame, leaving that determination to the JIM.

The JIM has already concluded that Syrian government forces were responsible for chlorine attacks on three villages in 2014 and 2015, and that the Islamic State group used mustard gas in 2015.

The OPCW is reviewing more than 60 cases of alleged chemical weapons use in Syria, including a recently-uncovered sarin attack on an opposition-held village on March 30.