Donald Trump pledged to build an "impenetrable, physical, tall, powerful, beautiful southern border wall" during an immigration policy speech on Wednesday in Arizona.

"We will build a great wall along the southern border," Trump said, while the crowd interrupted him with loud applause. "And Mexico will pay for the wall. Hundred percent. They don't know it yet, but they're going to pay for the wall.

He continued, "And they're great people and great leaders, but they're going to pay for the wall."

Trump's remarks come after his visit to Mexico on Wednesday to meet with the country's president, Enrique Pena Nieto. While some described the trip as a success, the Mexican president tweeted a message appearing to contradict Trump's suggestion that the two men did not discuss who would pay for Trump's border wall.

The GOP nominee traveled to Arizona to deliver a detailed policy speech about illegal immigration, and offered several points similar to his messaging throughout the GOP primary. In addition to building a southern border wall, Trump talked about ending the "catch and release" of illegal immigrants apprehended by government officials, having zero tolerance for criminal illegal immigrants, blocking funding for sanctuary cities, canceling President Obama's executive actions on illegal immigration, suspending the issuance of visas to any place where "adequate" screening does not occur, and ensuring that other countries take the people a Trump administration chooses to deport.

"Within ICE [Immigration and Customs Enforcement], I am going to create a new special deportation task force focused on identifying and quickly removing the most dangerous criminal illegal immigrants in America who have evaded justice just like Hillary Clinton has evaded justice, OK?" Trump said. "Maybe they'll be able to deport her."

Trump did, however, appear to leave the door open for some form of legal status for illegal immigrants already residing in the country, albeit several years into the future.

"Importantly, in several years, when we have accomplished all of our enforcement and deportation goals and truly ended illegal immigration for good ... and the establishment of our new lawful immigration system, then and only then will we be in a position to consider the appropriate disposition of those individuals who remain," Trump said. "That discussion can take place only in an atmosphere in which illegal immigration is a memory of the past, no longer with us."

Trump's speech was widely anticipated by immigration hawks, who sought answers about whether Trump was "softening" his approach to immigration as he previously indicated. In anticipation of his speech, Jessica Vaughan, the Center for Immigration Studies' director of policy studies who appeared onstage with Trump in a Fox News special from Texas, offered a mixed review of the ideas Trump had detailed on the trail.

"I get the sense that his instincts are very much in sync with the policies that we recommend for enforcement – especially with respect to the need to reverse the policies of the Obama administration to dismantle interior enforcement and to get better control of the border," Vaughan told the Washington Examiner. "I hope he will not be fooled by the slick and fake gimmicks like "paying back taxes" and "learning English" that the Gang of 8 tried to use to justify an amnesty. I think this discussion is a really an inappropriate distraction right now, and I do believe he understands that enforcement has to come first, to slow down illegal immigration, and restore some balance and fairness to our system, to avoid the mistakes of past amnesties."

Whether Trump's full plan on immigration will change the minds of any voters with 68 days remaining until the election is unclear.