Trudeau said Canada is also looking at other measures, including immigration. Other countries are considering offering asylum. About 300,000 Canadians live in Hong Kong.
China bypassed Hong Kong's Legislative Council to pass the sweeping legislation without public consultation.
The security law, which took effect Tuesday night, targets secessionist, subversive or terrorist acts, as well as collusion with foreign forces intervening in the city's affairs.
Under Beijing's direction, local authorities have moved swiftly to implement the law's sweeping conditions, with police arresting about 370 people Wednesday, including 10 on suspicion of directly violating the law, as thousands took to the streets in protest.