A sapling from the horse chestnut tree that Anne Frank watched from her World War II hiding place in an attic in Amsterdam has been planted and dedicated at U.N. headquarters to mark what would have been her 90th birthday.

Secretary-General Antonio Guterres said in a statement read at Wednesday's ceremony that the sapling "is a living symbol of both the legacy of Anne Frank" and the values of the U.N. which was established in the aftermath of the Holocaust.

Sharon Douglas, CEO of the Anne Frank Center for Mutual Respect which donated the sapling, said "the tree lived in the free air and represented to Anne a living symbol of hope and freedom."

Anne died at the Bergen-Belsen Nazi concentration camp in 1945 and her diaries became worldwide bestsellers.