"We aren't coming from Honduras because we want to, we come because we have to," Jorge Antonio Perez, a migrant who had crossed into Mexico, said.
An attorney for the 9-year-old's family in Texas said her heart stopped beating.
"You don't bring bone saws to fights," former Vice President Joe Biden said. "What is going on here? It's embarrassing, but it's also dangerous."
Parliamentary elections took place Saturday across the country, but were postponed in the province of Kandahar after a deadly attack on Thursday killed the region's police chief.
Scott Ostrem walked into a Walmart in Thornton, opened fire and left without saying anything, witnesses said. Three people were killed.