US border security preclearance procedures will be extended to two more Canadian airports. Currently nine cities have US officers processing passengers bound for the US. Toronto's Billy Bishop airport and Quebec City are coming to the list, possibly by the end of 2018. Billy Bishop, in downtown Toronto, is the base for Porter Airlines which has expanded its services to US destinations. Here is the current roster: https://www.cbp.gov/border-security/...s/preclearance