I don't think they rise to the level of war crimes by the ICC definition. More to the point, they would have to go through national authorities first. If, then, it were instance of a Canadian soldier engaged in sexual exploitation or abuse, it would be up to the Canadian authorities to investigate and provide accountability for that.
The point I was trying to make is that a number of countries have not taken the necessary steps to provide that accountability. The UN can't force them to do it. It has gotten more selective about which countries it's willing to allow to contribute, if they aren't taking those steps. Canada could play a leadership role in encouraging other substantial contributors to make sure they have the national accountability mechanisms to deal with those instances.