The move is being considered by Canada and other G8 members as part of a basket of sanctions targeting Russia over its military intervention in the Crimea region of Ukraine.
On Sunday, the group withdrew from preparations for June's G8 summit in Sochi to protest against what they see as Russia's violation of Ukraine's sovereignty.
"(Russian) President (Vladimir) Putin's action has put his country on a course of diplomatic and economic isolation, and that could well see Russia exit the G8 entirely," Harper said yesterday.
Canada's parliament meanwhile unanimously passed a motion to "strongly condemn Russia's provocative military intervention in Ukraine," and urged Russia to withdraw its troops.
Canada was the first Western nation to recognize an independent Ukraine in 1991.
Canada has a large Ukrainian community, there are 1.2 million Canadians of Ukrainian descent, according to the latest census.