Royal officials say the Duke and Duchess of Cambridge's daughter "was safely delivered" Saturday morning, less than three hours after checking into St. Mary's Hospital.
The newborn's name wasn't immediately announced but when her brother, Prince George, was born in 2013 royal officials waited two days before announcing his name.
Harper, who is on a surprise visit to Iraq, issued a statement saying "all Canadians were delighted today to learn of the birth of Her Royal Highness The Princess of Cambridge."
Harper says the Royal Family "holds a very special place in our country" and offered "heartfelt congratulations and very best wishes to the happy family."
Johnston said in a release that the new princess "will find an outpouring of affection from all Canadians and from people across the Commonwealth." Canadians can write wishes to The Duke and Duchess of Cambridge on the Governor General's website.
— With files from The Associated Press
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