KYIV, Ukraine -- Prime Minister Stephen Harper affirmed Canada's unwavering support of a new, westward looking Ukraine on Saturday as he became the first world leader to meet the country's newly inaugurated president.

Harper's meeting with Petro Poroshenko, who formally took the oath of office as president Saturday morning in Ukraine's capital of Kyiv, has significant political overtones in Canada. There are 1.2 million Canadians of Ukrainian descent, and they represent an important voting block.

Harper said that although Ukraine faces tough challenges, it can count on Canada's continued support.

"I am here on behalf of the government of Canada to express our solidarity with the government of Ukraine as you stand up for your unity, your liberty and your territorial integrity," Harper told Poroshenko in an ornate meeting room in his new presidential office building.

"We're fully behind you on that. I also do want to express the solidarity of the Canadian people with the Ukrainian people in your aspiration for a democratic European future and not a return to the country's Soviet past."

Harper said Poroshenko and his administration have some tough challenges ahead as they set out to rebuild Ukraine's political and administrative systems and grow what has become a hobbled economy.

Harper also met with U.S. Vice-President Joe Biden on the margins of Saturday's inauguration.

"They re-affirmed the need for Russia to recognize the result of elections in Ukraine, to stop the flow of weapons and militants across the border and to exercise its influence among armed separatists to lay down their weapons and end the violence in Ukraine," Harper's office said in a statement.

Poroshenko was elected on May 25, in a ballot that was monitored by 500 Canadian observers.

The vote was called after his predecessor, pro-Russian president Viktor Yanukovych, fled Ukraine in February following anti-Russian protests.

The popular uprising in Ukraine was sparked in November when Yanukovych reneged on an economic co-operation agreement with the European Union after pressure from Putin's Kremlin.

Paul Grod, president of the Ukrainian Canadian Congress, said he got good feedback on Poroshenko in meetings in Kyiv on Saturday with Ukrainian MPs, Canadian expatriates and others as part of a weeklong visit.

"They support his strong western focus and the need to elect a new parliament as this one is dysfunctional," Grod told The Canadian Press.

"He hit all key messages. Crimea is and will always be part of Ukraine, Ukraine will sign EU Association Agreement, unitary state with more local control, corruption is first thing that must tackled," he added. "People are saying he's the right person at this time for Ukraine."

Thousands gathered in Kyiv's streets in sweltering heat as the candy billionaire was about to be sworn in.

"Crimea is, was and will be Ukrainian. There will be no trade-off," Poroshenko said in his inaugural address to the country's parliament, the Verkhovna Rada.

Poroshenko said he hopes to negotiate a solution to the violence in his country's east, where pro-Russian separatist gunmen are continuing to cause unrest following Russia's annexation of Crimea in March -- a move denounced by Harper and other Western leaders as an illegal act.

Poroshenko said he wants to grant amnesty "for those who do not have blood on their hands" but added he would not negotiate with the pro-Russian insurgents, calling them "gangsters."

As the prime minister headed for the ceremony Saturday morning, the mood in the capital was subdued, with people strolling casually about in shirtsleeves under blue, sunny skies.

The Maidan, Kyiv's main protest point where more than 100 demonstrators were killed in February, was calm just before the inauguration, with small groups of people milling about what is still very much a fortress city, barricaded by piles of rubble and tires.

Anatoli Shanchuk, 61, a Kyiv consultant, strolled through the square headed for the crowds gathered at the inauguration several blocks away.

"I am optimistic," he said, but he didn't want to get his hopes up too high, just yet, over Friday's meeting in France between Poroshenko and Russian President Vladimir Putin in France at the Normandy invasion ceremonies.

"We consider this very important that people in North America, Canada especially, they are supporting us psychologically, financially, politically. The question is people in those countries really understand what is going on here."

In the square outside the parliament, the sharp thundercrack of ceremonial gunfire was heard just after the swearing in, making some flinch.

Andrei Tolchko, 43, and his family were making their way toward the inauguration site, one week after being forced to leave their home in Donetsk, in Ukraine's turbulent east.

Fighting is still raging in eastern Ukraine between government forces and Russian separatists.

"This is a great big day for our country. Of course we hope very much that something changes in our country," Tolchko said.

"We were pressed to here, to Kyiv, but we are glad to be here because in my native city now people with machine guns go everywhere, and it's not our people mostly."

He said the militants are "people from all over the world with crazy ideas," and that support an outdated Cold War notion of a "the great Russian."

Fighting continues to rage in eastern Ukraine between government forces and Russian militants.

Harper was on his way back to Ottawa on Saturday after a whirlwind visit, his second since March. He arrived in Kyiv early Saturday morning after attending the 70th anniversary of D-Day ceremonies in Normandy, France.