The conference focuses on the trans-Sahel, a desert area spanning four N. African countries where Al Qaeda operatives are believed to be training.
The killing of Edwin Dyer underscores the growing threat posed by militants in North Africa with links to global terrorist groups.
New leader Andry Rajoelina has asserted control as the South African Development Community threatens to suspend Madagascar.
The claim by Al Qaeda in the Islamic Maghreb that it holds hostages kidnapped more than a month ago fuels fears that the group is expanding its reach.
John Atta Mills took the oath of office Wednesday after a closely contested race.