In-short, you dont need US visa, you are not entering US, when you reach US border officer you have to mention you intend to Flagpole, they will know how to process you. One of the other member had posted a link that explains flagpoling.. Here's a website (not official) : https://www.immigrationstationcanada.com/post/what-is-flagpolingHello,
This is the first time I am hearing about Flagpoling. Do we need a USA visitor visa to cross the border first before we can attempt to Flagpole ?