US President Barack Obama has fiercely rejected Donald Trump's depiction of an America in crisis, arguing that violent crime and illegal immigration have plunged under his leadership to their lowest rates in decades.
Looking to November's election, Obama said, "We're not going to make good decisions based on fears that don't have a basis in fact."
At a news conference on Friday alongside Mexico's president, Obama sought to undermine two pillars of Trump's speech on Thursday night.
Trump said that if he is elected, "safety will be restored" at home and abroad.
"This idea that American is somehow on the verge of collapse, this vision of violence and chaos everywhere, doesn't really jibe with the experience of most people," Obama said.
The violent crime rate, he said, has been lower during his presidency than any time in the last three or four decades.
While he acknowledged an uptick in murders in some US cities this year, Obama said the violent crime rate today is still far lower than when Ronald Reagan was president in the 1980s.
The violent crime rate has been on a long-term decline, receding to 366 per 100,000 people in 2014. It was 758 per 100,000 in the peak year of 1991.
Obama used the same marker for immigration, describing today's rate of illegal border crossing as only a third of what it was during the Reagan administration, and lower than at any time since.
About 331,000 people were apprehended crossing the Mexican border illegally last year; there were 1.6 million arrests in 1986.
Speaking after an evening in which Trump laid out his case to be the next commander in chief, Obama grimaced noticeably when a reporter suggested the billionaire businessman's message appeals to working-class Americans.
Obama said he will let the US public decide if the vision of Republicans or Democrats for the nation is more persuasive.
Mexican President Enrique Pena Nieto tried to exercise restraint, saying he is ready to work with whoever prevails in the presidential election.
Previously, he had likened Trump's language to that of Adolf Hitler or Benito Mussolini, though he said such comparisons were taken out of context.
Trump on Thursday repeated his assertion that he would build a wall across the US-Mexican border "to stop illegal immigration, to stop the gangs and the violence, and to stop the drugs from pouring into our communities".
Of the US presidential campaign, Pena Nieto said, Mexico "will not give its opinion; it will not get involved".
Instead, he showered Obama with praise, calling him a "very good neighbour" and saying US-Mexican relations are in one of their best ever periods.
