President Trump had threatened to punish Mexico with tariffs to force them to step up their own immigration enforcement efforts.
Center for Immigration Studies Senior National Security Fellow Todd Bensman agreed the deal with Mexico is working.
"I think the return to Mexico/wait in Mexico policy is having an intended effect," said Bensman. "Migrants who are not going to be allowed to live illegally in the United States are going home. They're just going home."
Bensman said the wall is going up, despite what opponents say.
"This president is going to put that wall up by hook or by crook," said Bensman. "We're seeing it go up. We're going to see a lot more of it go up over the next year, leading into the election, and that's just the way it is."
Also in Arizona, crews are installing 30-foot steel fencing to replace older barriers. Construction is expected to take about 45 days. The taller fencing is being funded through a national emergency declaration by President Trump.