Russia accused of carrying out illegal chemical gas attacks against Ukrainian soldiers on the frontlines of 26-month invasion, as Zelensky once again pleads with US to approve major funding package to turn the tide of the war

Russia has been accused of carrying out illegal chemical gas attacks against Ukrainian soldiers. 

Several Ukrainian soldiers across the frontlines of the 26-month invasion that has devastated much of Ukraine revealed that Russian troops are using small drones to drop tear gas, among other chemicals, on their positions. 

Tear gas, also known as CS, is banned during wartime under the internationally-signed Chemical Weapons Convention, which both Russia and Ukraine are signatories of. Tear gas is commonly used by riot police across the world. 

Ukrainian soldiers who spoke to the Telegraph said Russian troops were dropping K-51 grenades, which according to experts is typically filed with tear gas. 

Ihor, a commander of a Ukrainian reconnaissance team that works near the frontline city of Chasiv Yar, in Donetsk Oblast, told The Telegraph: 'Nearly every position in our area of the front was getting one or two gas grenades dropped on them a day.'

He said that Russia was turning to the illegal weapons because its army was having difficulty using conventional artillery or drones: 'The only way for them to successfully attack us was with gas.'

He said that while tear gas is not always lethal or immediately incapacitating, gas attacks can often cause panic, which can lead to mistakes being made that Russian troops can capitalise on.

According to training documents, Ukrainian troops are now being told to stay where they are and endure the first few minutes of exposure to tear gas, instead of fleeing which may give their position away. 

After the first few minutes, the effect of the gas weakens. 

One commander who spoke to the Telegraph said that the poor quality armour and tools given to Ukrainian troops has compounded the problems massively. 

'We have gas masks, but in almost all cases they're very old, ex-Soviet models, and they're not very effective.'

Ukrainian president Volodymyr Zelensky said on Sunday that Kyiv will lose the war against Russia if the US Congress does not approve military aid to battle Moscow's invasion.

Republicans in Congress have been blocking tens of billions of dollars in military assistance for Kyiv for months.

'It is necessary to specifically tell Congress that if Congress does not help Ukraine, Ukraine will lose the war,' Zelensky said during a video meeting of Kyiv-organised fundraising platform United24.

Zelensky said it would be 'difficult' for Ukraine to survive without the aid.

He said that 'if Ukraine loses the war, other states will be attacked.'

Russia's invasion of Ukraine has dragged on for more than two years.