Addressing a bench of 17 judges from around the world, 74-year-old Aung San Suu Kyi, blamed the conflict on an uprising by separatist insurgents.
The meeting was held on the fringe of the Switzerland-based Universal Postal Union (UPU) congress.
Gambia is the 22nd to ratify the agreement which as a result went into effect.
Gambia's FM said on Monday it was up to the people of Togo to decide whether Gnassingbe should stay in power.
UN Secretary-General Antonio Guterres called for an end to the death penalty Tuesday, insisting it has "no place in the 21st century."
The head of a West African force maintaining security in The Gambia told AFP Friday that army officials loyal to veteran former leader Yahya Jammeh .
Five Gambian high school students denied US visas to attend an international robotics competition.