URGENTOTTAWA (AFP) - Canadian Prime Minister Stephen Harper has threatened he may join Washington in snubbing June's G8 summit in Russia over the country's military incursion into Ukraine, and recalled his ambassador to Moscow.

"We join our allies in condemning in the strongest terms (Russian) President Vladimir Putin's military intervention in Ukraine," Mr Harper said in a statement on Saturday.

"These actions are a clear violation of Ukraine's sovereignty and territorial integrity. They are also in violation of Russia's obligations under international law."