Ban appointed Swedish chemical weapons expert Ake Sellstrom to lead a fact-finding mission to investigate allegations of the use of chemical weapons in Syria.
Sellstrom served as an inspector for the U.N. Special Commission and the U.N. Monitoring, Verification and Inspection Commission for the disarmament of Iraq.
Ban last week received a formal request from Syrian Ambassador to the United Nations Bashar Ja'afari to look into claims anti-government forces used chemical weapons in Aleppo in mid-March.
Both sides to the conflict have issued similar claims, though a U.S. government spokesman said last week there was no new information about recent back-and-forth allegations of chemical weapons use in Syria.
Ban said the investigation would look into specific allegations raised by the Syrian envoy.
"I am, of course, aware that there are other allegations of similar cases involving the reported use of chemical weapons," he said.
The United Nations temporarily removed some international staff members in Syria because of security concerns, a U.N. spokesman said Monday. Ban said the investigation would begin as soon as it's safe to do so.