Russia and the United States were headed for a clash at the UN Security Council on Monday as Moscow prepared to veto a draft resolution that would impose sanctions on Syria.

The council will vote Tuesday on the text drafted by the United States, Britain and France that would punish 11 Syrians and 10 entities linked to chemical attacks in 2014 and 2015.

Russia has vowed to use its veto to block the measure, which would be the seventh time that Moscow has resorted to its veto power to shield its Damascus ally.

The vote scheduled for 11:30 am (1630 GMT) would mark the first major council action by the new US administration of President Donald Trump, who is seeking warmer ties with Russia. 

US Ambassador Nikki Haley was in Washington on Monday to join Trump and Vice President Mike Pence for a White House lunch, with foreign policy expected to be a focus of discussion.

"How much longer is Russia going to continue to babysit and make excuses for the Syrian regime?" she said on Friday following a closed-door council meeting to discuss chemical weapons use in Syria.

"People have died by being suffocated to death. That's barbaric."

The vote would see the Trump administration joining old allies France and Britain to confront Russia over its support for Syria.

Russian Deputy Ambassador Vladimir Safronkov said Friday that Moscow would veto the measure because it was "one-sided" and based on "insufficient proof."

The Syrian government has repeatedly denied using chemical weapons in the war that has killed 310,000 people since March 2011. 

Fears among European allies of a radical US shift on Russia subsided earlier this month when Haley leveled strong criticism at Moscow for its actions in Ukraine.

- Punishing those behind chlorine attacks -

The vote at the council comes as UN-brokered talks in Geneva to end the war in Syria were struggling to get off the ground while government air strikes continued, despite a ceasefire.

The draft resolution follows a UN-led investigation which concluded in October that the Syrian air force had dropped chlorine barrel-bombs from helicopters on three opposition-held villages in 2014 and 2015.

The joint panel of the United Nations and the Organization for the Prohibition of Chemical Weapons (OPCW) also found that Islamic State jihadists had used mustard gas in an attack in 2015.

Under the measure, 11 Syrians, mostly military officials, and 10 entities linked to chemical weapons development would be placed on a UN sanctions blacklist, hit by a global travel ban and assets freeze.

The draft resolution would also ban the sale, supply or transfer of helicopters and related matériel, including spare parts, to the Syrian armed forces or the government.

Chlorine use as a weapon is banned under the Chemical Weapons Convention, which Syria joined in 2013 under pressure from Russia.

The UN-OPCW panel had identified the Syrian air force units who dropped chlorine barrel-bombs on the villages of Qmenas, Talmenes and Sarmin in 2014 and 2015.

The head of Syrian air force intelligence, Major General Jamil Hassan, and Major General Saji Jamil Darwish, the commander of Syrian air force operations during the attacks on the villages, were on the proposed blacklist. 

The United States last month imposed sanctions on 18 senior Syrian military officers and officials over the use of chemical weapons.

Research by Human Rights Watch showed that Syrian government forces carried out at least eight chemical attacks during the final weeks of the battle for Aleppo, killing nine people and injuring hundreds more.

Source: AFP