Harper is travelling to the Netherlands for the Nuclear Security Summit, from March 24-25 in The Hague. But his first stop in Europe will be Kyiv on March 22 to meet the country's new prime minister, Arseniy Yatsenyuk.
"Canada remains united with its allies in recognizing the government of Ukraine, and in supporting Ukraine's territorial integrity and sovereignty," the prime minister said in a statement Friday.
"We will continue to work with our allies to support efforts to restore the country to stability and unity so that the people of Ukraine can thrive and prosper free of intimidation and threat."
Harper last visited Ukraine in October 2010.
Harper will arrive in the days following this Sunday's hastily called referendum in Crimea, a Ukrainian region now under control of pro-Russia politicians and militias.
The vote will offer Crimeans two options: to join Russia or an independent Crimea. Remaining part of Ukraine is not an option.
Foreign Affairs Minister John Baird says Canada won't recognize the outcome of the referendum.
"I cannot stress clearly enough that it will not be business as usual," he said Friday.
"The international community will not recognize this stunt of a referendum that now threatens to turn from an invasion to an annexation."
Harper is also to visit Germany for two days following his time in the Hague, where he will meet with Angela Merkel, chancellor of Germany, and Joachim Gauck, the German president.
Canada announced earlier this week it was contributing $220 million to an international effort to bail out the government of Ukraine.
Last week, the European Union proposed a $15-billion aid package, and the U.S. committed $1 billion. The new government in Kyiv has said it needs $35 billion for this year and next.
Yatsenyuk told the United Nations Security Council on Thursday that Russia is carrying out a "military aggression" that has "no reason and no grounds."
U.S. Secretary of State John Kerry met with Russia's foreign minister on Friday in an 11th hour bid to ease tensions, but Sergey Lavrov emerged from the meeting to say the Russians and the West have "no common vision" on the events in Ukraine.
He added, however, that Russia has no plans to invade eastern or southern Ukraine despite a continuing military buildup.
Baird says Canada and its allies are giving diplomacy a chance to work, but adds he's "not optimistic."
"While it appears to be a remote possibility, we want to hope that Russia will choose to take a different course in the coming hours," he said.
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