Washington will impose new sanctions on Russia, US ambassador to the United Nations Nikki Haley has said – as Western allies look to put some diplomatic clout behind military strikes launched on Syria in the wake of an apparent chemical weapon attack.

“Russian sanctions will be coming down,” Ms Haley said during on appearance on CBS’ Face the Nation, adding that the new sanctions are expected to be announced by treasury secretary Steve Mnuchin on Monday.

It comes as the US, UK and France – who took part in the retaliatory strikes – push a draft resolution ahead of a meeting of the UN’s Security Council, also on Monday, which includes a proposal for an independent investigation into alleged chemical weapons attacks that identifies those responsible.

Both the Syrian government and its ally Russia have denied involvement in the chemical attack, which occurred in the Syrian town of Douma and is believed to have killed dozens of civilians. Moscow has suggested that allegations over the attack are false, as well as claiming it was coordinated by Britain. The US and France have both said they have proof Syrian president Bashar al-Assad was behind the chemical weapon use.

The UN resolution forms part of a wider strategy to enforce the elimination of chemical weapons, which the US says Russia has repeatedly failed to do despite being the guarantor of a 2013 deal to achieve that. The resolution also calls for action over the wider civil war in Syria, such as allowing medical evacuations and aid convoys, and the enforcement of a ceasefire. The draft resolution will put pressure on Moscow, with US sanctions looking to achieve the same effect.

“Secretary Mnuchin will be announcing those on Monday if he hasn’t already, and they will be going directly to any sort of companies that were dealing with equipment related to Assad and chemical weapons use,” Ms Haley said.

Syria air strikes: US, UK and France joint military action Show all 21 1 /21 Syria air strikes: US, UK and France joint military action Syria air strikes: US, UK and France joint military action A picture released by the French Defence audiovisual communication and production unit (ECPAD) shows the launching of a cruise missile from a French military vessel in the Mediterranean sea towards targets in Syria overnight. The United States, France and Britain carried out a wave of punitive strikes against Bashar al-Assad's Syrian regime in the early hours of April 14 in response to alleged chemical weapons attacks. AFP/Getty Syria air strikes: US, UK and France joint military action Rafale warplanes being prepared for take off at the Saint-Dizier aerial military base, eastern France. Media reports state that the United States, France and Britain launched military strikes in Syria to punish President Bashar Assad for an apparent chemical attack against civilians and to deter him from doing it again. EPA Syria air strikes: US, UK and France joint military action Damascus skies erupt with missile fire as the US launches an attack on Syria targeting different parts of the capital. President Donald Trump announced airstrikes in retaliation for the country's alleged use of chemical weapons. AP Syria air strikes: US, UK and France joint military action A map show the location of the air strikes carried out by the US-led coalition in Syria overnight. US Department of Defense Syria air strikes: US, UK and France joint military action The wreckage of a building described as part of the Scientific Studies and Research Centre compound in the Barzeh district, north of Damascus. AFP/Getty Syria air strikes: US, UK and France joint military action Royal Air Force tornado jets take off in the early hours from RAF Akrotiri airbase in Cyprus to conduct air strikes in Syria. Four Tornado jets fired Storm Shadow missiles "at a military facility -- a former missile base -- some 15 miles (24 kilometres) west of Homs, where the regime is assessed to keep chemical weapon precursors," the defence ministry said in a statement. AFP/Getty Syria air strikes: US, UK and France joint military action Map of where the air strikes hit in Syria released by the Pentagon. A Syrian military statement says the US, Britain and France fired 110 missiles during a joint attack on targets in Damascus and outside. Pentagon Syria air strikes: US, UK and France joint military action A photo released on the Twitter page of Hezbollah's "Central War Media" account shows night footage of flares above Damascus seen through a night-vision device as Western strikes reportedly hit Syrian military bases and chemical research centres in and around Syria's capital. US, France, and Britain announced the joint operation. AFP/Getty Syria air strikes: US, UK and France joint military action The preliminary damage assessment of Barzah research and development centre before and after the air strikes, released by the Pentagon. Pentagon Syria air strikes: US, UK and France joint military action The preliminary damage assessment of Him Shinshar chemical weapons bunker before the air strikes. Pentagon Syria air strikes: US, UK and France joint military action The preliminary damage assessment of Him Shinshar chemical weapons bunker after the air strikes. Pentagon Syria air strikes: US, UK and France joint military action The wreckage of a building described as part of the Scientific Studies and Research Centre compound in the Barzeh district, north of Damascus. AFP/Getty Syria air strikes: US, UK and France joint military action The wreckage of a building described as part of the Scientific Studies and Research Centre compound in the Barzeh district, north of Damascus. AFP/Getty Syria air strikes: US, UK and France joint military action The wreckage of a building described as part of the Scientific Studies and Research Centre compound in the Barzeh district, north of Damascus. AFP/Getty Syria air strikes: US, UK and France joint military action The preliminary damage assessment of Him Shinshar chemical weapons storage site before and after the air strikes, released by the Pentagon. Pentagon Syria air strikes: US, UK and France joint military action The preliminary damage assessment of Him Shinshar chemical weapons storage site before the air strikes. Pentagon Syria air strikes: US, UK and France joint military action The preliminary damage assessment of Him Shinshar chemical weapons storage site after the air strikes. Pentagon Syria air strikes: US, UK and France joint military action A British military Typhoon aircraft lands at the Sovereign Base Area (SBA) of Akrotiri, a British overseas territory located ten kilometres west of the southern Cypriot port city of Limassol, following US, British and French strikes on Syria. Syrian state media slammed Western strikes on Saturday as illegal and "doomed to fail," after the US, Britain and France launched a joint operation against the Damascus.government. Huge blasts were reported around the Syrian capital, moments after the three Western governments announced they were striking Syria's chemical weapons capabilities. AFP/Getty Images Syria air strikes: US, UK and France joint military action The preliminary damage assessment of Him Shinshar chemical weapons bunker before and after the air strikes, released by the Pentagon. Pentagon Syria air strikes: US, UK and France joint military action The preliminary damage assessment of Him Shinshar chemical weapons bunker before the air strikes. Pentagon Syria air strikes: US, UK and France joint military action The preliminary damage assessment of Him Shinshar chemical weapons bunker after the air strikes. Pentagon

Ms Haley told CBS the fact that Assad was making the use of chemical weapons “more normal and that Russia was covering this up, all that has got to stop”.

The UN envoy also said that the Trump administration’s response takes into account other attacks using chemical weapons, as Mr Trump tweeted in defence of his use of the phrase “mission accomplished” when talking about the US, UK and French strikes on three alleged chemical weapons-related facilities.

The US president said: “The Syrian raid was so perfectly carried out, with such precision, that the only way the Fake News Media could demean was by my use of the term ‘Mission Accomplished.’

“I knew they would seize on this but felt it is such a great Military term, it should be brought back. Use often!”

Ms Haley said military action was only taken because diplomatic efforts have been stymied by Moscow.

On Saturday, the UN Security Council rejected a separate resolution tabled by Russia calling for condemnation of “aggression” by the US and its allies. Only three countries – Russia, China and Bolivia – voted in favour of the resolution at the end of an emergency meeting. Eight countries voted against and three abstained.

Syria air strikes: How events unfolded

When asked on Fox News Sunday about “how our relationship with Russia has changed this week”, Ms Haley said that relations are “very strained”, but that the US was still hoping for a better relationship.

“If you look at what Russia is doing, they continue to be involved with all the wrong actors, whether their involvement in Ukraine, whether you look at how they are supporting Venezuela, whether you look in Syria and their way of propping up Assad and working with Iran; that continues to be a problem,” Ms Haley said. She called the poisoning of former Russian spy Sergei Skripal and his daughter Yulia in Salisbury – which the UK has blamed on Russia – “another issue”.

“Right now they don’t have very good friends and right now the friends that they do have are causing them harm,” Ms Haley said, referring to Russia and the use of sanctions. “I think they’re feeling that.”

Ms Haley told the Security Council on Saturday that President Trump had made clear US forces were “ready, locked and loaded” to mount further strikes if there were signs that Assad was planning to use chemical weapons again.

The Russian president Vladimir Putin warned on Sunday that further Western attacks on Syria would bring chaos to world affairs.

Mr Putin made his remarks in a telephone conversation with Iranian counterpart Hassan Rouhani, with a Kremlin statement saying the pair agreed that the Western strikes had damaged the chances of achieving a political resolution in the multi-sided, seven-year Syrian civil war.

“Vladimir Putin, in particular, stressed that if such actions committed in violation of the UN Charter continue, then it will inevitably lead to chaos in international relations,” a Kremlin statement said.

Senior Russian legislator, Evgeny Serebrennikov, the deputy head of the defence committee of Russia’s upper house of parliament, told the RIA news agency Moscow was ready for new sanctions from the US.