Officials in one Arizona border town are opposed to President Donald Trump’s border wall to restrict illegal immigration.

“A wall would only represent a slap to the face of our Mexican neighbors,” John Doyle, mayor of border town Nogales, Ariz., told USA TODAY. “It sends the wrong signal to the rest of the world.”

Nogales, Ariz. and Nogales, Sonora, Mexico, are separated currently by a largely ineffective border fence. Many on the U.S. side of town, including county sheriff Tony Estrada, have friendships and familial ties across the border.

Trump “insulted my people,” Estrada said of the president’s plans to build a wall. “When he said that, I took it personally. That’s not right. He shouldn’t be talking about people like that, people you don’t really know. If he knows them, he’s probably had them doing his construction work.”

The fence along the border is like “iron curtains,” Estrada said. Since the fences were first constructed in the mid-1990s, authorities have discovered more than 100 tunnels running beneath the border in Nogales.

Mexican officials are also opposed to closing off the border between the two countries. “People don’t want more walls, they want more exchange,” Graco Ramirez, governor of the Mexican state of Morelos, told USA TODAY. Another Mexican politician climbed the border fence in Nogales last week to protest the wall.

U.S. Customs and Border Protection are moving forward with the design phase of the border wall project, and have asked developers and engineering firms to pitch prototypes for the massive structure.

Secretary of the Department of Homeland Security Gen. John Kelly told Congress on in February that he anticipates the wall project “will be well underway in two years.”

The total cost and timeline of the project are unclear, but it will likely be a lucrative endeavor for the companies selected. Trump said the cost could be around $12 billion, and House Speaker Paul Ryan floated the number $15 billion. A Department of Homeland Security report obtained by Reuters earlier this month put the cost at $21 billion for the entire project.

Follow Thomas Phippen on Twitter

Send tips to thomas@dailycallernewsfoundation.org.

Content created by The Daily Caller News Foundation is available without charge to any eligible news publisher that can provide a large audience. For licensing opportunities of our original content, please contact licensing@dailycallernewsfoundation.org.