Prime Minister Stephen Harper praised Ukrainians for casting their ballots in Sunday's presidential vote as exit polls suggest that candy tycoon Petro Poroshenko has won the election in the first round.

In a tweet on Sunday, Harper congratulated Ukrainians for "taking this important step towards rebuilding democracy."

"(Canada) will continue to stand by you," he said.

Full results from the election are expected on Monday, but exit polls conducted by three Ukrainian agencies have suggested Poroshenko, 48, has captured 55.9 per cent of the vote in a crowded field of 21 candidates. If that number holds, a runoff election next month with the second-place finisher, former Prime Minister Yulia Tymoshenko, would be avoided.

Harper's tweet on Sunday followed a statement from Foreign Affairs Minister John Baird, who also applauded Ukrainians for participating in the election during a "critical phase" of their country’s history.

"The long lines of people who came out vote in these elections are an undeniable affirmation of how deeply Ukrainians value freedom and democracy, and demonstrate a clear commitment to building a better future, free from Russian-sponsored subversion and violence," he said on Sunday.

Baird -- who has previously said that Canada "cannot sit by while Russia illegally occupies Ukraine" -- also offered his continued support to the country.

"Canada will continue to work with the Ukraine government to help restore the country’s economic and political stability."

Over the past few months, many Ukrainian-Canadians have been closely watching the conflict as ongoing Russian aggression gripped their home country. Many also took part in protests in Canada in an attempt to convince some of the world's biggest powers to force Russia to release its hold on their homeland.

On Sunday, many of them again voiced their opinion as the lineup to cast a ballot stretched far beyond the borders of Ukraine. In Toronto, nearly 5,000 people who were eligible to vote descended on the Ukrainian consulate.

"This choice is very important for my country," Kateryna Iekymova, 22, told CTV Toronto. "I think it determines (the) future of my country."

Voting at the consulate was relatively calm as many quietly lined up to cast their vote -- a stark contrast to what was happening at some polling stations in eastern Ukraine where pro-Moscow separatists had smashed ballot boxes.

"It is really sad to know that some of the electoral commissions were literally risking their lives," Nataliya Labtayeva told CTV Toronto.

"Like many other Ukrainians, I realized this year how important it is to be voting and choosing who I believe will be a better leader for my country."

Sunday's election comes approximately six months after the outbreak of protests that led to the ouster of former president Viktor Yanukovych, and about two months after Russia’s annexation of Crimea.

Many leaders in the West were keeping a close eye on the presidential election, hoping the vote will help bring some stability to the troubled eastern European country.

Sunday's election took place amid weeks of fighting in eastern Ukraine where pro-Russian separatists have been clashing with government troops.

In advance of Sunday's vote, Canada sent a large delegation to observe the presidential election. A total of 500 observers were sent to Ukraine, including Senator Raynell Andreychuk, who headed the mission, and former Ontario premier Mike Harris.

Liberal MP Chrystia Freeland, who is Ukrainian-Canadian, was also in the country to observe the voting process.

Conservative MP James Bezan, who was also part of the election observation team, said turnout for the election was strong despite some challenges in the east, where pro-Russian rebels had attempted to block people from voting.

Bezan said arrangements were made to allow Ukrainians living in those regions to cast their ballots at other more secure polling stations.

In total, less than 20 per cent of the polling stations in the eastern regions of Donetsk and Luhanks were open during election.

Across the country, about 60 per cent of the electorate turned out for the vote, according to Ukraine’s central elections commission.

With a report from CTV Toronto's Scott Lightfoot and files from The Canadian Press and The Associated Press