In an interview on Sunday, GOP candidate Scott Walker discussed the importance of building a wall along the border between the U.S. and Canada, the longest international border in the world at 5,525 miles, according to the Associated Press.

The conversation surrounding illegal immigration and border control has been a pivotal one for current republican candidates who have focussed manily on the Mexican border.

During an interview on "Meet the Press," Walker justified the necessity for a Canadian border wall by saying that the U.S. spends millions of dollars on security at airports and Mexican border ports and that it "only makes sense" to keep a watchful eye on the Canadian border as well, reports the Washington Post.

He called the topic of a Canadian border a "legitimate" issue, clarifying his comment later in the interview.

"It starts with securing the homeland. It's not just about building a wall and securing our borders. It's also about making sure our intelligence community has the ability for counterterrorism and the ability to go after the infrastructure they need to protect us," he said, according to the Huffington Post.