Gov. Scott Walker this weekend said it's a "legitimate" idea to consider building a wall between the U.S. and Canada to deter terrorists.

In a 30-minute taped interview with NBC's "Meet the Press" host Chuck Todd, Walker emphasized his desire to "secure" the country's borders to boost safety from terrorists, focusing on the border with Mexico. But when pressed by Todd, Walker said extending that effort to the country's 5,525-mile border with Canada is worth looking into.

"Why are we always talking about the southern border and a fence there? We don't talk about a northern border — where, if this is about securing the border from potentially terrorists coming over," Todd said, asking Walker if he would build a wall on the northern border, too.

"Some people have asked us about that in New Hampshire," Walker responded. "They raised some very legitimate concerns, including some law enforcement folks that brought that up to me at one of our town hall meetings about a week and a half ago. So, that is a legitimate issue for us to look at."

Walker and other GOP candidates seeking the 2016 presidential nomination have focused heavily on immigration issues — especially front-runner Donald Trump, who has called for a wall to be built between the U.S. and Mexico and that Mexico should pay for it.

But secure borders also help fight terrorists, Walker told cadets at The Citadel in Charleston, S.C. on Friday while laying out his foreign policy agenda. This element of his plan prompted Todd's questions about the lack of campaign rhetoric about also securing the country's northern border with Canada.

In December 1999, a 34-year-old Algerian man living in Montreal, who planned to bomb the Los Angeles International Airport, was arrested in Port Angeles, Wash., while trying to cross the border.

Cook County Commissioner Frank Moe, who represents the tip of Minnesota's Arrowhead region, told the Star Tribune that the idea of erecting a wall along a border consisting primarily of water "sounds pretty crazy to me," and costly, as well. To Moe, the question was: Why? "What's he trying to protect us from — Canadian hockey players or moose?" he added. "It's hard not to have fun with it."

In the NBC interview, Walker also dismissed a recent Marquette University poll that showed 39 percent of Wisconsin residents approve of his job performance. Fellow 2016 GOP hopeful Ohio Gov. John Kasich has a job approval rating of 61 percent, Todd gave as a comparison.

"You should want someone who doesn't care about the next election — they care about the next generation. That's the difference," Walker said in response. "I went out and pushed big, bold reforms in my first term — I haven't let up. I'm the kind of leader that's going to go out and say 'I don't care about the next election, I care what's right for the next generation.' "

Last winter, Walker surged into the top tier of the Republican presidential race. But his candidacy has stumbled as Trump has dominated the news.

The newest Des Moines Register-Bloomberg News Iowa poll, released on Saturday night, showed Walker's support plummeting. Iowa is the linchpin of the governor's early-state strategy. Now, Walker is the favorite of just 8 percent among likely GOP caucusgoers, running third behind Trump.

Former Minnesota Gov. Tim Pawlenty, who unsuccessfully sought the GOP nomination four years ago, said in an interview that he sees both opportunities and challenges for Walker as he tries to regroup.

"He's a hybrid candidate who can appeal to both base conservatives and not scare the establishment," Pawlenty said. "So he's in a good spot in terms of the potential territory he appeals to. But he's still got to go out and rise to the occasion and close the sale."

Staff writer Tony Lonetree and the Washington Post contributed to this report