PORT-AU-PRINCE, Haiti (AP) _ U.N. Secretary-General Ban Ki-moon on Friday appointed a seasoned humanitarian worker to serve as his Acting Special Representative in Haiti to oversee the world body's peacekeeping mission in the Caribbean nation.

Nigel Fisher, a Canadian, replaces outgoing U.N. envoy Mariano Fernandez, who is leaving the job after 20 months. Fernandez has said he may consider a foray into politics in his native Chile.

Fisher has been Ban Ki-moon's Deputy Special Representative for Haiti since 2010. That year, a massive earthquake struck the country, killing tens of thousands of people and leaving 1.5 million more homeless.

He joined the international organization in 1977, and has held senior positions in the U.N. Office for Project Support Services, the U.N. Mission of Support in Afghanistan and the children's agency UNICEF. His assignments have taken him to a dozen countries in Asia, the Middle East and Africa.

As head of peacekeeping, Fisher will oversee the country's security at a politically delicate time. Haiti this year is supposed to hold legislative and local elections, which are expected to be fraught by protests.

The U.N. peacekeeping mission in Haiti, known by its French acronym Minustah, has been in the country since 2004, when a violent rebellion ousted then-President Jean-Bertrand Aristide. The force currently is authorized to have up to 6,700 military personnel.