“We’re going to build a wall.”

Promised by the newly sworn-in 45th president of the United States, Donald Trump, the topic of a wall stretching across the border of the U.S. and Mexico has been a highly controversial topic since Trump began to run in 2016, and it is uncertain if it will ever become a reality.

Trump was initially scheduled to meet Mexican president Enrique Peña Nieto in early February, but the meeting was canceled over renewed tensions about the wall. “This morning we have informed the White House that I will not attend the meeting scheduled for next Tuesday with the POTUS,” Peña Nieto tweeted. Earlier that morning, Trump had also tweeted, “If Mexico is unwilling to pay for the badly needed wall, then it would be better to cancel the upcoming meeting.” The New York Times reported that Trump had later fired back, accusing Mexico of burdening the United States with illegal immigrants, criminals, and a trade deficit.

He spoke about the cancellation at a gathering of congressional Republicans in Philadelphia, noting that they had mutually agreed to not get together and that the U.S. would not fund the wall, adding that the meeting was pointless unless Mexico treated America fairly. BBC wrote that while Trump claimed the total cost of the wall was going to be $10-$12 billion, Senate Majority leader Mitch McConnell said at the same gathering that it would cost $12-$15 billion. The cost is likely to soar even above that, as the fence would extend into more remote and mountainous areas and even private property that would have to be purchased. A study by The Washington Post estimated the cost would be around $25 billion.

The Mexican president, however, is insistent that Mexico will not pay for the wall. In a video released to Twitter, he states, “Mexico does not believe in walls. I’ve said time again; Mexico will not pay for any wall” (translated from Spanish by CNN). Peña Nieto also added that he will step up protection for immigrants and that Mexico expects and offers respect. However, Trump has signed an executive order to start the construction of the wall and did say in an interview with ABC News that American taxpayers will have to pay for the wall at first.

With the wall planned to span one thousand miles, it will undoubtedly be expensive, and ways to pay for it are still being debated. Trump’s spokesman Sean Spicer said that they planned to raise a 20% border tax on Mexican imports to help pay for the wall, though he added that they were still considering other options. Forbes argued that the amount of Mexican goods imported would have to be quadrupled to pay for the whole wall, even if the cost was spread over ten years. Other options currently being considered to pay for the wall are…

• Banning or taxing remittances (a sum of money sent, especially by mail, in payment for goods or services or as a gift). One possibility is that Trump would pass a law preventing Mexicans living in the U.S. from wiring money back to their home country. The hope is that it will force Mexico to pay for the wall so the law is not passed. The other possibility is to tax the remittances, but the issue with that is that affected Mexicans may avoid wiring the cash and find undocumented third parties to do it instead.
• Increasing travel visa and border-crossing fees. This would target countries that have a bad record with illegal immigration (which includes Mexico) for higher visa fees. Fees on cars and individuals crossing the border would raise money as well.

Eighth grader Aida Hamideh expressed her opinion about the wall: “The wall isn’t smart because we have ties with [Mexico], and lots of our goods come from there. If we build the wall, then things will just get worse and then people will feel rebellious and start more protests and riots.” Fellow student Vince Ferrante agreed, saying, “I think it’s completely crazy. It’s gonna cost a lot of money, and chances are, it won’t keep [immigrants] out.”