Henry Romero/REUTERS
During the press conference, Trump said that a private conversation between the two leaders on Wednesday was productive, and he called Peña Nieto a "friend."
But he noted that differences remain between the two countries over how to manage trade relationships between the two nations, and who would fund Trump's proposed border wall between the US and Mexico.
"I was straightforward in presenting my ideas on the effects of trade and immigration on the United States," Trump said, summarizing the private meeting.
Though the Republican presidential candidate said that they discussed the wall, the two leaders "did not discuss who pays for the wall." Trump has repeatedly insisted at campaign rallies that Mexico will fund the wall.
Donald Trump: We didn't discuss who pays for the wall https://t.co/SfJWzo0Bw4 https://t.co/PtSehY7BqX
- CNNPolitics (@CNNPolitics) August 31, 2016
Trump noted that his priorities included ending illegal immigration, ending drug trafficking, and improving the trade relationship between the US and Mexico.
"No one wins in either country when human smugglers and drug traffickers prey on people, when cartels commit acts of violence," Trump said. "I shared my strong view that [the North American Free Trade Agreement] has been a far greater benefit to Mexico than it has to the United States and it has to be improved so that workers in the United States can benefit."
"Even if we do not agree on everything, I trust that together we will be able to find prosperity and security."
For his part, while Peña Nieto noted the importance of the historic alliance, he acknowledged that they "may not agree on certain topics."
"Any close relationship needs to be visited and renewed from time to time and see what has worked and what hasn't," Peña Nieto said.
Trump launched his campaign last year with a broadside that many Latinos in the US and Mexico found offensive, saying that Mexico was "pushing the bad ones" into the US.
Trump repeatedly insisted that the US had "become a dumping ground" for Mexico, and threatened a trade war with the country if the two nations could not renegotiate trade agreements like the North American Free Trade Agreement.
On Wednesday, the Republican presidential candidate spared on Twitter with the former Mexican president, who said Trump was "not welcome in Mexico" due to his threat to make Mexico pay for a wall along the southern US border and deport 10 million immigrants living in the US without permission.