However, images of the scene near the border crossing separating Tijuana from San Diego, Calif., over the weekend showed a cloud of tear gas that sent people running and screaming, including families with young children in diapers.
One woman, Cindy Milla, told the Wall Street Journal that her child fainted when the tear gas was thrown.
“I felt that my face was burning, and my baby fainted,” she said. “I ran for my life and that of my children.”
WATCH: Tear-gassed mother recounts U.S. border chaos
Reuters reporter Kim Kyung-Hoon said she was there and snapped a picture of a Honduran mother grabbing the arms of her five-year-old twin daughters as they frantically ran from a tear gas canister spewing fumes.
“I thought I was going to die with them because of the gas,” Maria Meza told Reuters, adding that she was shocked the U.S. border agents fired the canisters near women and children.
The U.S. government said customs officers had fired off the canisters after a group of migrants had attempted to cross the border violently, throwing projectiles at them. Thirty-nine migrants were arrested.
Meza said three canisters landed around her and her five kids.
“It wasn’t right. They know we are human beings, the same as them. It wasn’t right that they did that to the children,” she said.
WATCH: Trump says migrants in Mexico ‘will not enter’ the U.S., speaks about why tear gas was used
On Monday, Trump was asked by reporters if it was okay to use tear gas on children.
“We didn’t. We don’t use it on children,” he said.
But later that day, Trump seemed to acknowledge children were affected, asking: “Why is a parent running up into an area where they know the tear gas is forming, and it’s going to be formed and they were running up with a child?”
He said it was “a very minor form of the tear gas itself” that he assured was “very safe.”
According to a Vox report, tear gas is considered a “chemical weapon” under international law — but it isn’t illegal for domestic law enforcement. This case is complex, however, because tear gas canisters were thrown across the border.
Trump also claimed some of the women are not really parents but instead “grabbers” who steal children so they have a better chance of being granted asylum in the U.S. However, he did not provide any evidence to support the claim.
The incident over the weekend marked an escalation of tensions between the U.S. and a group of Central American migrants who have been walking for more than a month in hopes of gaining entry to the country to escape violence and poverty.
WATCH: Migrants run from tear gas launched near U.S. border fence
The images of children fleeing tear gas prompted sharp criticism from some lawmakers and charities. British aid group Oxfam said the use of tear gas was shameful.
“Images of barefoot children choking on tear gas thrown by U.S. Customs and Border Patrol should shock us to our core,” Vicki Gass, Oxfam America senior policy adviser for Central America, said in a statement.
On Tuesday, White House adviser Kellyanne Conway said migrant mothers who were tear-gassed at the U.S. border should enter the country peacefully and legally.
WATCH: Conway tells tear-gassed mothers, come legally
She also blamed photographers who take pictures of migrant women for not “helping.”
“I have great compassion for any mother who wants a better life for her children,” Conway told reporters. “And that’s why I believe if people taking pictures of these women really care about them, they won’t go for optics, they will go for opportunity. Who is helping them to realize how they can immigrate here legally?”
—With files from Reuters and Global News’ Maham Abedi
© 2018 Global News, a division of Corus Entertainment Inc.