Several migrants told UPI they worry Mexican authorities will seek to remove them from the camp and deport them after Sunday's march, the surge at the border and the use of force in response by US authorities.
"That has happened before and, if we are rocked, that would happen again tomorrow", he told reporters.
USA authorities made 69 arrests Sunday.
President Donald Trump said on Monday that the tear gas was "very safe". "So we have to have border security", he added.
Critics denounced the action by border agents as overkill, but Trump kept to a hard line.
Scott also defended the agents' decisions to fire tear gas into Mexico, saying they were being assaulted by "a hail of rocks". 139 of them were children who were accompanied by total strangers, while 87 fake families were separated due to adults falsely pretending to be under-aged.
"We were deluded into believing that we had already reached the United States, and that they would grant us asylum", Colon told AFP.
That sentiment is shared by another Tijuana resident, 48-year-old Lucia Barrio who says it is better to send them back to where they came from, "because they brought children with them, and those children are suffering".
Questioning why parents were "running up into an area" with children "where they know the tear gas is forming", Trump then made his suggestion that those with children were just opportunistic "grabbers".
Following the incident, Customs and Border Protection (CBP) Commissioner Kevin McAleenan defended the firing of CS gas canisters by agents saying it was to stop an "extremely unsafe situation" after primarily adult males began throwing rocks.More news: Everything You Need to Know About NASA's Mars InSight
More news: Liverpool insisted upon unusual clause in Philippe Coutinho's Barcelona contract
More news: Did Liverpool's Salah send a message to Ramos with celebration against Watford?
At this time, Defense Department officials said there's been no change to plans to have servicemembers deployed along the southwest border home by December 15, as Defense Secretary Jim Mattis outlined in a news briefing on November 21.
Women and children were among those trying to protect themselves from tear gas fired by the authorities, sparking condemnation from activists and some politicians.
Mexico's new foreign minister also called on the Trump administration to contribute to development projects to help create jobs in Central America to stem the flow of migrants from the impoverished region, suggesting an appropriate figure would start at $20 billion.
Trump, who for weeks has been condemning the caravan, lashed out once more.
Cindy Martinez of San Vicente, El Salvador, said she had been about to cross the concertina wire to the USA side when the tear gas was launched.
She and hundreds of other Central American migrants were blocked by Mexican police and staged a protest in front of the border, some rushing the U.S fence.
Border Patrol said its agents found the woman and her children Friday about a mile east of the San Ysidro port of entry, the largest crossing between San Diego and Tijuana, Mexico, where scenes of chaos have erupted in recent days as members of a migrant caravan highlighted by Republicans as a midterm election issue have begun to arrive at the border.
"The way things went yesterday ... I think there is no chance", Mejia said. It must be "objectively reasonable and necessary in order to carry out law enforcement duties" and used when other techniques are insufficient to control disorderly or violent subjects.
But it's also possible that Sunday's clash was borne of increasing desperation caused by the hardening of the policies, said Rachel Schmidtke, program associate for migration at the Woodrow Wilson International Centre for Scholars Mexico Institute.