MEXICO CITY — On Mexican soil for the first time as the Republican presidential nominee, a firm but measured Donald Trump defended the right of the United States to build a massive wall along its southern border, standing up for the centerpiece of his immigration plan in a country where he is widely despised.
But within hours of Trump's visit, a dispute arose over the most contentious part of the billionaire's plans to secure the U.S. southern border — his insistence that Mexico must pay to build that wall.
When answering questions from adjacent lecterns before a Mexican flag after his meeting at the official residence of the country's president, Enrique Pena Nieto, Trump said Wednesday the two men didn't discuss who would pay for a cost of construction pegged in the billions.
Silent at that moment, Pena Nieto later tweeted, "At the start of the conversation with Donald Trump I made it clear that Mexico will not pay for the wall."
With the meeting held behind closed doors, it was impossible to know who was telling the truth. But the difference in how Trump and Pena Nieto recalled their talk was an example of the political risk taken on by two unpopular politicians who arrived at the meeting having spent months quarreling from afar.
Trump began his campaign by deriding Mexico as a source of rapists and criminals and piled on in the months to come as he attacked Mexico over free trade, illegal immigration and border security. Pena Nieto responded by condemning Trump's language, saying those were the sort of words that gave rise to Adolf Hitler.
Pena Nieto did not repeat such criticism Wednesday, but acknowledged Trump's comments had "hurt and affected Mexicans."
"The Mexicans deserve everyone's respect," he said.
The trip and the later dispute, arriving 10 weeks before America's presidential Election Day, came just hours before Trump was to deliver a highly anticipated speech in Arizona about illegal immigration. That has been a defining issue of his presidential campaign, but also one on which he has appeared to waver in recent days.
Trump stayed on script after the meeting, reading a statement from notes and politely answering shouted questions from reporters about his promise to force Mexico to pay for a wall along the border between the two countries.
"We did discuss the wall. We didn't discuss payment of the wall," Trump said.
Writing later on Twitter, Pena Nieto said the subject was among the first things the men discussed. He has for months said "there is no scenario" under which Mexico would pay for the wall.
"From there, the conversation addressed other issues, and developed in a respectful manner," he added.
But Trump would have the last word about the wall on Wednesday. At the rally in Phoenix, he insisted that Mexico will pay for the wall he wants to build along the length of the southern border.
During a speech on immigration, Trump said that Mexico will pay for the wall, "100 percent."
"They don't know it yet, but they're going to pay for" it, he said.
Continuing his tough talk on immigration, Trump said he will order the immediate detention of all known immigrants in the United States illegally who have been arrested for crimes.
He said that on the first day in office he will "issue detainers for illegal immigrants who are arrested" and initiate immediate proceedings to remove them.
For people caught crossing the border illegally, Trump referenced the 1950s-era "Operation Wetback." He said that "we will take them great distances" instead of sending them just across the U.S. border.
Trump said, "We will take them to the country where they came from."
He said his administration will take a hard line on criminal illegal immigrants. He said the United States will be "moving them out on Day One."
To thunderous applause, Trump announced that he will seek legislation to block federal funding for so-called sanctuary cities that shelter immigrants in the country illegally.
His immigration policy would not only be tough on people here illegally, but also on the countries where they came from. Trump said he will force nations to accept the return of their citizens who have been deported from the United States after being accused of crimes.
He said the United States "will ensure that other countries take their people back when we order them deported," but did not offer any details on how this would be accomplished.
Trump claimed that at least 23 countries refuse to take their citizens back after they've been ordered to leave.
"Not going to happen with me folks," he promised.
Trump also stated that 13,000 people in the United States illegally who were ordered back to their home counties remained in the country between 2008 and 2012, and committed more crimes, including killings, sexual assaults and "some of the most heinous crimes imaginable."