>> on the first trip to the southwest border, homeland security chief john kelly said in a vicious titan table for the wall. >> it will be built where it's needed most and then beef filled in. >> he saw the challenges firsthand. over my shoulder we have mexico. one of the most heavily traffic areas along the border. border control agents pick up at least 600 people any given day. they call it the rgb sector. the rio grande valley is notorious. it's about 100 miles as the crow flies but more than 300 miles to secure their shoreline. >> the protection of our border involves discussion of physical barriers but also of technological sensors, things like that. it's a layered approach. >> the strategy is pushing more resources to the border.