Russia says it will veto a UN Security Council resolution drafted by the US, Britain and France to impose sanctions on Syria over allegations of chemical weapons use.

"I just explained our position very clearly to our partners. If it is tabled we will veto it," Russia’s Deputy UN Ambassador Vladimir Safronkov said on Friday following a closed-door council session.

He further rejected the proposed measure as “one-sided,” saying it is based on “insufficient proof” and contradicts “the fundamental principle of presumption of innocence until the investigation is over.”

The US, France and Britain are pressing to put their proposed resolution to a vote early next week in order impose sanctions on Syrian authorities accused of using chemical weapons.

This file photo shows UN chemical weapons experts carrying samples from one of the sites of an alleged attack near Damascus on August 28, 2013. (Photo by Reuters)

The Syrian government, however, has repeatedly and fiercely denied using chemical weapons in the foreign-imposed conflict that has so far killed 310,000 people since March 2011.

The draft resolution follows a UN-led probe that accused the Syrian military in October of carrying out at least three chlorine gas attacks on the villages of Qmenas, Talmenes and Sarmin in 2014 and 2015.

The joint panel of the United Nations and the Organization for the Prohibition of Chemical Weapons (OPCW) further concluded that Daesh terrorists had used mustard gas in an attack in 2015.

The proposed measure would slap a global travel ban and assets freeze on 11 Syrians, mostly military officials, as well as 10 entities allegedly linked to chemical weapons development.

It would further prohibit the sale, supply or transfer of helicopters and related materiel, including spare parts, to the Syrian government and its armed forces.

File photo of a UN helicopter engaged in the efforts to destroy chemical weapons in Syria.

The US and its allies have repeatedly used chemical weapons as a pretext to pressure the Syrian government. Damascus volunteered to destroy its chemical stockpile in 2014 following a poisonous attack outside the capital.

The allegations of chemical arms use are still made against Syria even as the dismantling of the country's entire stockpile of chemical weapons as well as relevant production facilities was supervised by the UN.

Foreign-backed militants have repeatedly used chemical weapons against Syrian troops, some of which have been verified by UN officials, but the attacks have often been ignored by Western governments.

In December 2015, a cousin of former Libyan dictator Muammar Gaddafi said that chemical weapons used in Ghouta which were blamed on the Syrian government were in fact stolen from Libya and later smuggled into Syria via Turkey.