Republican nominee Donald Trump is addressing supporters in a major speech on immigration in the border state of Arizona, just hours after he met Mexican President Enrique Pena Nieto in Mexico City.

He opened his speech by detailing the stories of undocumented immigrants who committed violent crimes, telling thousands in the convention centre in downtown Phoenix that he had "met with many of the great parents who lost their children to sanctuary cities and open borders".

Later, he pledged to impose "ideological certification" for immigrants seeking to enter the US and raged against low-skilled undocumented immigrants who compete with US citizens for jobs.

He also reaffirmed his pledge to build a wall on the country's southern border with Mexico, as supporters chanted "Build a wall".

"They don't know it yet, but they will pay for the wall," he said of Mexico.

Immigration has been a defining issue of Trump's presidential campaign, with inflammatory comments about Latinos, Muslims and other minorities.

Protesters gathered in Mexico City as the presidential hopeful visited the country which he has derided  as a  source of rapists and criminals  coming to the US.

In a speech on Saturday in Iowa, Trump said he would seek to institute a tracking system to ensure undocumented immigrants who overstay their visas are quickly removed, and would propose an e-verify system to prevent undocumented residents from gaining access to welfare and other benefits.

"If we don’t enforce visa expiration dates, then we have an open border - it’s as simple as that," he said.

Source: Al Jazeera And Agencies