And she says her office stands ready to join the investigation, if requested to do so.
UN chief Ban Ki-moon announced his decision to launch an investigation into possible use of chemical weapons in Syria on Thursday (21 March).
Speaking to journalists in Geneva, Spokesman Rupert Colville says if chemical weapons do indeed turn out to have been used, this can only be described as an abominable and depraved act.
He said, "we hope these reports turn out to be incorrect, because if they are true this terrible conflict will have plunged to new depths. The use of chemical weapons would most likely be either a crime against humanity or a war crime. The High Commissioner echoes the Secretary- General's call that if such a crime has been committed these responsible must be held accountable."
He went on to say that the High Commissioner reiterates her call to all parties to the conflict to immediately halt attacks against civilians, and to go beyond that — to actually provide for their protection.