A Canadian in Ukraine has made the excruciating decision to flee Kyiv for Poland in the hope that he can soon get safe passage to Canada.

In the three months leading up to Russia's invasion of its neighbour, Dayton Snow of Medicine Hat, Alta., had been living in Kyiv with his father Darren and his Ukrainian wife, teaching English.

Snow's father Darren told CTV National News' National Affairs Correspondent Omar Sachedina that the violence he heard outside his apartment makes him want to leave the country like his son.

"Is there going to be a blast through the window at that time?" Darren Snow said. "I was there for three night hearing bombs. You can't sleep. It's very stressful."

On Wednesday, Darren Snow made it to Lviv in order to get a bus out of Ukraine. Even with a ticket leaving from Lviv's central bus depot, travellers aren't guaranteed a spot on one of the buses destined for Poland.

According to the UN refugee agency UNHCR, more than 800,000 people have fled Ukraine as of Wednesday morning to neighbouring countries since the start of Russia's invasion last week, adding that the number is on track to surpass one million by the end of the day. And earlier this week, UNHCR spokeswoman Shabia Mantoo cautioned that the outflows from Ukraine could make it the source of the “biggest refugee crisis this century.”

At Lviv's terminal, Snow waited for his bus to Poland, which was half an hour late. With no information, Snow went to look for where the bus might pull in, but the next one that did still wasn't his.

"It's crazy right now as you can see," Snow said. "Full-blown crisis."

Hours later, Snow's bus pulled into the station, but Snow and his friend had to run to make it to the bus to get a seat.

Snow made it onto the bus as the final passenger accepted. Snow later texted Sachedina to say that he had made it safely to Poland, and that he is grateful to have a place to stay before trying to get back to Canada.

Of the nearby nations accepting refugees, Poland has accepted more than half of those fleeing Ukraine. Polish President Andrzej Duda has voiced his support for Ukraine, including by sharing a website on his Twitter account highlighting the ways in which Poland is helping refugees from Ukraine.

Immigration, Refugees and Citizenship Canada has said it is expediting the process for Canadian citizens like Snow, as well as permanent residents and their accompanying immediate family members to return to Canada.