Mr Wallace said Russia’s invasion of Ukraine has “faltered” and is “starting to fail”, as he pledged more financial and military support to the eastern European nation’s defence.
The Defence Secretary said it is important to understand that fighting and loss of life is still taking place, but claimed Russia is “starting to fail in many areas”.
He added: “They have failed so far and are unlikely to ever succeed in occupying Ukraine.
“Their invasion has faltered and constantly been remodified to the extent they are really only focusing in parts of the south and in the east, a long, long way away from their three-day so-called special operation.
“Three days are now over 150 days and nearly six months in, with huge significant losses of both equipment and indeed Russian personnel.”
Denmark joined the UK in offering more aid to Ukraine at a conference in Copenhagen on Thursday, co-hosted by Mr Wallace.
The Defence Secretary also said: “President Putin will have gambled that come August, come a few months in, we will have all got bored of the conflict and the international community would have gone off in different directions. Well, today is proof of the opposite.
“We have come out of this meeting with more pledges of finance, more pledges of training and more pledges of military aid, all designed to help Ukraine win, to help Ukraine stand up for its sovereignty and indeed to ensure that President Putin’s ambitions fail in Ukraine as they rightly should.”
Mr Wallace said allies will need to soon start buying in weapons from other countries or “placing orders in factories to increase ammo supply to Ukraine” as their own reserve stocks are depleted.
The Ministry of Defence earlier confirmed it would send more weapons to Ukraine to help it defend against Russia’s invasion.
This included multiple-launch rocket systems, as well as precision guided missiles which can strike targets up to 50 miles away, designed to defend against Russian heavy artillery.
Mr Wallace said: “Our continued support sends a very clear message: Britain and the international community remain opposed to this illegal war and will stand shoulder-to-shoulder, providing defensive military aid to Ukraine to help them defend against Putin’s invasion.”
Ukrainian troops have been trained in the UK on how to use the launchers, and the UK has also committed to training 10,000 Ukrainian soldiers in infantry battlefield skills over the coming months.
Canada, Denmark, Sweden, Finland and the Netherlands have all announced they will be supporting the programme.
The UK has previously supplied Ukraine with various weapons, including the NLAW anti-tank missile launcher, which was considered instrumental in the initial defence against Moscow’s invasion.
It comes as the International Fund for Ukraine has been expanded, with £250million of the £1billion total given by the UK to provide military equipment and other support to the armed forces.
This will ensure the provision of new weapons and the maintenance and repair of existing kit.