London, April 2 -- Shirley Ayorkor Botchwey assumed office as the Commonwealth's Secretary General on Tuesday. She is the second African and first African woman to lead the association of 56 countries which make up a third of the world's population and more than a quarter of the United Nations membership.

Botchwey succeeds Patricia Scotland, whose nine-year term ended in March. She has pledged to advance the values of the Commonwealth Charter at a time of growing global tensions and shifting alliances.

Speaking at the Commonwealth Secretariat's headquarters in London on Tuesday, Shirley Ayorkor Botchwey acknowledged the scale of the challenges confronting the world.

She said, "The world we woke up to today is unlike any we have seen in...