"As Canadians we emphasize our very strong support — and we emphasize this to all the countries in the region — our very strong support for the territorial integrity and the respect of the territorial integrity of Ukraine," Prime Minister Stephen Harper said at an event in Toronto.
"We remain very supportive of the Ukrainian people in their desire for democracy and a better future."
While not specifically naming Russia in his comments, Harper called the reports out of Ukraine "worrying."
Foreign Affairs Minister John Baird, speaking from Kyiv, went further, singling out Russia directly.
Baird said he was calling on Ukraine's neighbours to respect its sovereignty "and avoid any actions that could prove and appear provocative."
"With this in mind I am concerned that Russian military exercises so close to the Ukrainian border are not helpful at this time when emotions and when tensions are running high."
The comments came as members of Ukraine's new government accused Russia of a "military invasion," saying Russian troops have taken up positions around a coast guard base and two airports in Crimea.
Baird said he welcomed a statement from Russian Foreign Minister Sergey Lavrov that Russia would respect Ukraine's territorial sovereignty.
Baird said the government is working with its allies to try to determine "fact from fiction" on what is happening in the Crimea.
"We expect the Russian Federation to honour the commitments that it made in the Budapest declaration and we certainly don't apologize for standing with the Ukrainian people their struggle for freedom," Baird added, referring to the 1994 international agreement on Ukraine's borders.
The Harper government's comments echoed a stand taken by the United States and other European countries.
U.S. Secretary of State John Kerry called Lavrov on Friday to express Washington's concerns over military activity in Crimea that could further inflame tensions.
Kerry told reporters that Lavrov had once again repeated Russian President Vladimir Putin's pledge to respect Ukraine's sovereignty and territorial integrity, while also pointing out that Russia has broad interests in the former Soviet republic.
A new Ukraine government was formed this week after three months of often violent protests against former president Viktor Yanukovych, who has fled the country and is currently in Russia.
Russia, which has a major naval base in Crimea, confirmed Friday that armoured vehicles from its Black Sea Fleet were moving around Crimea for "security" reasons, but it did not respond to accusations from members of Ukraine's new government that it had begun a military invasion.
In Kyiv, Ukraine's parliament adopted a resolution demanding that Russia halt steps it says are aimed against Ukraine's sovereignty and territorial integrity, and sought help from the UN Security Council to protect it from its powerful neighbour.
UN spokesman Martin Nesirky said the council had scheduled a meeting Friday afternoon, but any action by the council is highly unlikely because Russia is a veto-wielding permanent member and can block any action.
Foreign Affairs Minister John Baird is in Kyiv this week and is expected to meet with the new Ukrainian prime minister, Arseny Yatseniuk on Friday.
Ukraine's population is divided in loyalties between Russia and the West, with much of western Ukraine advocating closer ties with the European Union while eastern and southern regions look to Russia for support.
Crimea, a southeastern peninsula of Ukraine that has semi-autonomous status, was seized by Russian forces in the 18th century and was once the crown jewel in Russian and then Soviet empires.
It became part of Ukraine in 1954 when Soviet leader Nikita Khrushchev transferred jurisdiction from Russia, a move that was a mere formality until the 1991 Soviet collapse meant Crimea landed in an independent Ukraine.
— with files from the Associated Press.
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