National Security Adviser Susan Rice is handing over her outgoing post as US representative to the UN to a former journalist.
Samantha Power, 42, made her name documenting the international community’s failure in Bosnia, specifically to stop the massacre at Srebrenica in 1995.
She inherits a role which has a current focus on the Syrian conflict.
Al Jazeera's James Bays reports from the UN.
Source: Al Jazeera