CSIS is involved in the security screening aspects of the illegal migration flow, but most of the questions have rightly been directed to my colleagues from CBSA and the RCMP, because they are the ones at the border dealing with the people as they come in. As has been clearly articulated, nobody about whom there are any security-related concerns is allowed to come in until those concerns have been resolved.
On May 10th, 2018. See this statement in context.