WATCH: Eugene Yunak speaking to UTV's Peter Moor.
A Ukrainian national who lived and worked in the UK and Ireland says he feels he has no choice but join the country's Territorial Defence in its fight against Russia.
Russia launched a "full-scale invasion" of Ukraine on Thursday with reports of explosions heard across the country including in the capital Kyiv, Kharkiv, Dnipro and Odesa.
President Zelensky cut diplomatic ties with Russia and declared martial law, while urging Ukrainians to remain calm and stay home.
There have been reports of dozens killed. In a televised address, Prime Minister Boris Johnson said the UK was prepared to resort to military measures.
Russian President Vladimir Putin warned any interference would lead to "consequences you have never seen."
"We don't know what's going to happen so I think all hands on deck is warranted," Eugene Yunak who lives in Lviv, told UTV.
"I want to increase my contribution. But now I think it's time really to step it up a little bit and join the active forces," Eugene said, in between packing up his belongings.
"I don't feel like I have a choice. I feel like this is what we have to do, what I personally have to do."
Eugene said his family was struggling with his decision to take up arms.
"I don't think anybody's happy about this, my family isn't but they understand and respect my decision and that's what I'm going to do," he said.
"I feel like this is the most pressing need and if I can make a difference, I have to and I'm awfully nervous, you can tell but I don't really have a choice."
Whilst Eugene lives over 300 miles away from Kiev in the west of Ukraine, he stills feels in danger - especially given that he lives near an airport which he believes could be targeted by Russian forces.
"We do expect and there have been warnings for the local area of the city so we are moving out of here and my plan here now is to jump on my bike and go hit the official territory defence forces and get signed," he said.
Eugene, like many other people in his country, have been braced for an invasion, given Russia's previous actions.
"Whatever I say I will do from then on. Like many Ukrainians, I’ve been practicing my shooting skills and physical fitness, but the army needs to be well coordinated," Eugene said.
"The official military is the best way to achieve it given the circumstances we are in.
"I feel encouraged by the military response we have organised, and I think this ain’t gonna be a fast walk-in-the-park takeover, especially given the support we are seeing from our partners across the globe," he added.
A 'Peace for Ukraine' rally is scheduled to be held at Belfast City Hall on Friday at 6pm.
We'll have more on this and the developing situation in Ukraine on UTV Live at 6.