Biden told a South Carolina rotary club that he voted for a border fence despite other Democrats opposing the measure.
"Folks, I voted for a fence, I voted, and unlike most Democrats -- and some of you won't like it -- I voted for 700 miles of fence," he said, in the video unearthed by CNN.
"But, let me tell you, we can build a fence 40 stories high -- unless you change the dynamic in Mexico and -- and you will not like this, and -- punish American employers who knowingly violate the law when, in fact, they hire illegals. Unless you do those two things, all the rest is window dressing," he added.
The video came as Biden entered the race to be his party's challenger against President Donald Trump during the 2020 elections. One of the top criticisms from Democrats has surrounded Trump's tough immigration stances and, in particular, his demand for a barrier across the southern border.
Biden, in the video, indicated he was more concerned about drugs than he was about immigrants themselves crossing the border.
"Now, I know I'm not supposed to say it that bluntly, but they're the facts, they're the facts. And so everything else we do is in between here. Everything else we do is at the margins. And the reason why I add that parenthetically, why I believe the fence is needed does not have anything to do with immigration as much as drugs," he told the audience.
It's unclear what Biden's thoughts on the wall are now that it's become a central platform of the Trump agenda. Biden, perceived as more of a moderate Democrat, has pushed for tougher security through enhanced technological capabilities as an alternative to barriers.