EXCLUSIVE: Revealed: The mystery Canadian sniper who left his fiancée and baby son behind to take on the Russians in Ukraine - as he warns Putin he 'won't hesitate to squeeze the trigger when the time comes'

• e-mail

The world holds its breath as deranged Vladimir Putin prepares to unleash the full force of Russia's troops in a David and Goliath battle for Ukraine's historic capital, Kyiv.

But the despot's soldiers will pay a devastating price when they finally set foot inside the besieged city, according to 'Wali' - an elite sniper and western freedom fighter who plans to pick them off with pinpoint accuracy.

A veteran of two tours of Afghanistan with the Canadian Royal 22nd Regiment, Wali left behind a fiancée, one-year-old son and a comfortable life as an IT programmer to answer Ukraine's plea for foreign recruits.

Weeks later he's hidden high above the streets of Kyiv in a secret nook ready to greet the first Russian invader he sees with a bullet from his .338 rifle.

'I don't like the idea of shooting anyone. But when the time comes to squeeze the trigger I won't hesitate,' Wali tells DailyMail.com in an exclusive phone interview.

'If Putin really wants Kyiv he is going to have to pay a huge price. Nobody wants the Russians here and everyone will resist. The damage we can do to them will be crazy. They will lose so many lives it will become another Stalingrad.'

Canadian army veteran and sniper identified only as 'Wali' is hidden high above the streets of Kyiv ready to greet the first Russian invader he see with his .338 rifle

People and medics help a wounded resident of a house destroyed by shelling as Russia's attack on Ukraine continues in Kyiv

Russia's infantry has advanced to within 15 miles of the shuttered city of nearly three million inhabitants, according to latest reports

Wali has asked to go by the nickname he was given in Afghanistan in case former KGB strongman Putin learns his identity and tries to target his family in Quebec.

While his loved ones gathered Saturday to celebrate his son's first birthday, Wali spent the day hunkered down in an abandoned building overlooking what he will only disclose as a 'strategic location' on the outskirts of Kyiv.

Despite fierce resistance and a string of humiliating setbacks, Russia's infantry has advanced to within 15 miles of the shuttered city of nearly three million inhabitants, according to latest reports.

But Wali tells DailyMail.com that he and his band of Ukrainian brothers will have the upper hand once Putin's men pour into the streets - and stray into his crosshairs.

'This is a huge, built-up city, not some village. Looking out from where I am now I can see so many structures and buildings to shoot from, so many places to hide weapons and launch ambushes from. They won't know what has hit them,' Wali vows.

'The Russians have already failed to take Kharkiv and Mariupol, which are smaller cities. There is no way they can hold on to Kyiv. It will be better for everyone if they decide not to attack.'

It's been barely two weeks since Wali was sat in front of a TV in Canada watching Putin launch the largest military onslaught in Europe since World War II.

With a new career in IT and a young family, Wali's fighting days were well and truly behind him - or so he thought.

It was his boss, a Ukrainian-Canadian with family members trapped in besieged cities, who persuaded him it was his 'duty' to answer President Volodymyr Zelensky's call to arms.

It's been barely two weeks since Wali was sat in front of a TV in Canada watching Putin launch the largest military onslaught in Europe since World War II

Wali honed his sharpshooting skills during a 12-year career in the Canadian army

Like a 'firefighter who hears the alarm ringing' Wali says he joined his colleague on the next flight to Poland, leaving behind a fiancée as bewildered as she was scared by his decision to throw himself into brutal warfare 4,000 miles away.

'She was very afraid, she said we need you here, your son needs you. But eventually she calmed down and she said ok, do your duty but please be safe, don't take any risks,' Wali says.

 'There were a lot of emotions as I left. You don't know when you're going to be back, or whether you're even going to make it back. But I know I have a duty to my family as well as to the world, I won't stay here any longer than I have to.

'The saddest thing for me was missing my son's birthday celebration. I watched a few minutes over the phone. I was here in the dark, in an abandoned building with my flashlight - it felt like I was on a different planet to them.'

Wali says he was greeted with hugs and handshakes as he crossed from Poland into Ukraine on March 3, passing columns of refugees trudging in the opposite direction to reach safety.

He would soon become infamous after giving a brief interview to the Canadian Broadcasting Corporation which went viral and morphed into outlandish headlines about how the 'world's deadliest sniper' was gunning for Putin.

'If that's what they want to believe, then it's not a bad thing. People need these kinds of stories in a war, it's a boost for morale,' says Wali, modestly.

'I'm a good sniper, yes, but I don't deserve this much attention. I don't want to take away from the courage of the other soldiers here.'

Wali honed his sharpshooting skills during a 12-year career in the Canadian army.

He was first deployed to Afghanistan in 2009 when he spent six months fighting alongside US troops in Kandahar, returning a year or so later to mentor Afghan police.

After leaving the military in 2015 Wali embarked on his first stint as a freedom fighter, joining up with Kurdish forces for four months as they battled ISIS terrorists in northern Iraq.

Without the air support, training and hi-tech weaponry he was accustomed to, Wali says he and his allies learned to wage war with whatever they could get their hands on.

Russia has intensified its attacks on Kyiv with air strikes raining down on the city, while fighting and artillery fire rage around the suburbs

Russian President Vladimir Putin meets with Deputy Prime Minister Dmitry Grigorenko at the Kremlin in Moscow today

'There were no helmets, no ballistic plates, not enough ammunition. I went out on patrol sometimes with just two magazines,' he recalls.

'There was an occasion where we pushed into a village on the back of a bulldozer using the big shovel as protection. I was hanging on thinking this is insane, I cannot survive this but the Islamic State fighters were so shocked they ran away.

'Some of them hid in a house so the Kurds set it alight then shot them dead when they rushed out. I can still hear the bullets flying past me. It was absolutely brutal, a day I will never forget.'

Wali says the western portions of Ukraine he passed through en route to Kyiv have been largely unscathed and - so far - he's not encountered the level of violence and destruction he experienced in Iraq.

His reputation as a feared marksman helped him win over Ukrainian commanders who entrusted him with a $6,000 military-grade .338 sniper rifle and assigned him to the front ranks of the city's defense.

The Finnish-built gun, equipped with high-grade optics, is typical of the Western weapons he's accustomed to using and can kill at a range of 1,400 meters (1,531 yards).

'It's a high quality rifle. It will do the job but I'll be sad when I have to use it. Every time I shoot it's a failure for everyone involved,' Wali laments.

'A lot of these Russian soldiers are just boys themselves. I can't help thinking that not too long ago they were babies like my son. But I'll do what's necessary.'

With Russia and Ukraine set to meet this week for further peace talks there's a glimmer of hope that a ceasefire can be agreed without Kyiv's streets becoming a bloodbath.

Russian airstrikes caused heavy damage to a Ukrainian military base in Yavoriv, just 12 miles from the Polish border, on Sunday - killing at least 35 people and leaving 134 more wounded

People retrieve belongings from an apartment in a block which was destroyed by an artillery strike in Kyiv, Ukraine

The nightmare scenario is that Putin rejects any deal and decides instead to decimate the city with airstrikes in a warped show of force.

'We cannot underestimate the Russians as they have lots of firepower,' Wali adds, gravely.

'There are ways to protect yourself, you can move from building to building, you can change location while they adjust fire.

'So it's a mix of luck and skill, like rolling a dice. The better you are the better the odds are but the dice can always fall on the wrong number. You can get killed no matter your skill level or who you are.'

If the worst happens, Wali hopes his young son will grow up understanding that his dad died fighting for something greater than a bloody battle for frozen territory on the eastern fringe of Europe.

'I would like him to be proud of me and to grow up believing in the same values that I'm fighting for,' he tells DailyMail.com.

Our interview is likely one of the last calls Wali will make before switching off his cell phone to avoid giving his position away to the advancing Russians.

With unshakeable belief, he adds: 'I'm not just doing this for Ukraine, I'm doing this for everyone. Ukraine is the frontline for freedom.'