Harper's itinerary will also include Poland and Italy, where he will push for progress on Canada's comprehensive free trade pact with the European Union — negotiated, but not yet ratified — and also meet with Pope Francis.
As Harper's last major international trip before the expected October federal election, it will be one of his last opportunities to project himself as an experienced, capable world statesman to voters back home.
It was one year ago that Harper last travelled to Ukraine, where he affirmed Canada's unwavering support for the country, meeting with Petro Poroshenko on the day he formally took the oath of office as president.
Simmering unrest continues despite the September ceasefire between Ukraine forces and Russia-backed separatists in eastern Ukraine.
At least two civilians and three Ukrainian troops were reportedly killed Monday in eastern Ukraine.
"We've been working hand in glove on a number of initiatives to help protect Ukraine's independence and its democracy and also working on its economy and improve the governance," Harper said.
Harper will meet with Poroshenko and Prime Minister Arseniy Yatsenyuk on Saturday before heading to the G7 in Germany. It will mark the second year in a row that Russia has been excluded from what used to be the G8.
Harper has repeatedly and stridently singled out Russian President Vladimir Putin for violating Ukraine's territorial sovereignty, and has shown no interest in engaging with him directly, unlike some other G7 leaders.
At the G7, Harper said he and his fellow leaders would discuss the two biggest threats currently facing the West: the fight against jihadism and the continuing unrest in eastern Ukraine, which he blamed on "the ongoing aggression of the Putin regime."
A new report released Monday by the United Nations says that 6,400 people have now been killed in more than a year of fighting in east Ukraine.
Marko Shevchenko, the Ukraine charge d'affairs to Canada, was effusive in his praise for Canada's support prior to a meeting with Harper at his Langevin Block office.
That support includes 200 soldiers to western Ukraine to help improve the combat skills of the country's troops, something Shevchenko said would increase his country's capacity "to survive in the front line."
Shevchenko also affirmed the Canada-Ukraine bond, which will have federal electoral implications in October because there are 1.2 million Canadians of Ukrainian descent.
"It's needless to say that relations which Ukraine has with Canada are deeper and much more significant than with any other country in the world. Last year, Ukrainians have chosen democracy, prosperity and European future and my country feels permanent friendly support of (the) Canadian government on this long and very difficult way," Shevchenko said.
"Unfortunately, Ukraine at the same time is facing the biggest threat in its modern history —I mean Russian aggression, Russian annexation of Crimea."
Poland also views Canada as a top ally in the ongoing crisis with Russia, the biggest threat to Europe's security since the end of the Cold War.
Harper ends his trip in Italy, where in addition to the Pope he will also meet Italian Prime Minister Matteo Renzi.
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