Former U.S. secretary of state Hillary Clinton says Russian President Vladimir Putin is using his country's energy resources to intimidate his opponents.

Clinton told an audience in Calgary that Putin's incursion in Ukraine follows a pattern of behaviour he first established with the invasion of Georgia in 2008.

She said Putin cherishes a greater vision of Russia similar to its position in the past.

Clinton warned that the West's dealings with the Ukrainian crisis have reached a delicate moment.

Clinton also criticized Russia's reopening of old Soviet bases in the Arctic.

She said the move risks militarizing the entire area.