Short of having access to Xinjiang and access to files, it is very difficult to completely confirm the numbers. What we have called on governments to do, including this government, is to work together in a concerted way with other governments that are concerned about the human rights abuses happening in Xinjiang, to call for an independent UN mechanism to be able to enter Xinjiang to investigate the abuses there and determine the scale of the abuses as well. If that's done in a concerted way with many other governments, it might have success.
On October 18th, 2018. See this statement in context.