Trudeau was in Moncton, N.B., today where he accused Stephen Harper of being out of touch with Canadians on the issue.
There have been renewed calls for an inquiry since the death of Tina Fontaine, a 15-year-old aboriginal girl found dead in Winnipeg.
Harper said earlier this week that Fontaine's death was a crime and should not be viewed as a "sociological phenomenon."
Trudeau says there is no question that her death was a crime, but Canada needs to determine what is behind the high number of native women who have disappeared or been murdered and an inquiry is the best way to do that.
Trudeau was campaigning alongside New Brunswick Liberal Leader Brian Gallant for that province's election.