Houngbo starts his term as director-general of the International Labor Organization on Saturday, taking over the ILO leadership from British trade unionist Guy Ryder, who is stepping down after 10 years.
"It is indeed a proud yet humbling experience to stand here as the first African recipient of these three keys," Houngbo said after Ryder handed them over marking the change of leadership.
"It is testimony... to the unfaltering determination of an entire region that the ILO should continue its struggle to make decent work a global reality," he added.
The ILO is unique in the U.N. system in that its 187 member states are equally represented by governments, employers and workers.
Three keys, for that tripartite nature, were needed to open the gates of its first purpose-built headquarters in Geneva.Houngbo, 61, was elected by member states in March.
"I take up office at a difficult moment in history. A moment of unparalleled uncertainty for our generation and deep-felt doubt for what the future might hold," he said.
Headquartered in Geneva, the ILO aims to promote rights at work, encourage good employment opportunities, enhance social protection and strengthen dialogue on work-related issues