Trump's policy took children away from parents who were apprehended crossing the border illegally.
Democratic gubernatorial candidate Lupe Valdez says she teared up when she heard audio of children crying in detention families.
He focused on the fact that young migrants separated from parents are likely to be reunited, unlike the victims of murders.
"We must maintain a Strong Southern Border", Trump tweeted Friday morning. "We can not allow our Country to be overrun by illegal immigrants as the Democrats tell their phony stories of sadness and grief, hoping it will help them in the elections".
The federal Family Case Management Program - terminated under the Trump administration - compiled a ideal record of attendance by migrants at court hearings, and a 99 percent appearance record at immigration check-ins, according to a 2017 report by the Homeland Security inspector general.
The "Angel Families", as they've been dubbed, reiterated Trump's point, emphasizing that the separation from their loved ones was permanent, as they were killed by "illegal aliens", and not temporary, like the migrant families at the border. The Justice Department wanted the prosecutions to continue.
Administration officials met late Thursday and on Friday to try to hash out these differences as well as to come up with a plan for reuniting the migrant families that have already been separated. "The word "permanently" being the word that you have to think about".
"We weren't lucky enough to be separated for five days or 10 days, we're separated permanently", she said.
'We need people to come in, but they have to be people that love this country, can love our country and can really help us to make America great again, ' he said. And then when they commit crimes, we're so surprised.
They also spoke against the trump administration's "Zero-tolerance policy" calling it barbaric and traumatizing to the children.
Media captionNisa Mickens, 15, was killed by an MS-13 gang including undocumented immigrants.
But his assertion has been contradicted by a number of studies, including one by the Cato Institute and another in the journal Criminology that found that places with higher percentages of undocumented immigrants do not have higher rates of crime.
A US Customs and Border Patrol spokesperson said the bus carried "family groups" being transferred into the custody of Immigration and Customs Enforcement.
"I always hear that - 'Oh no, the population is safer than the people that live in the country.' You've heard that, fellows, right?" I say, is that possible? "They should be letting people go to the outside so they can work and contribute to this country". Outside conservative groups labeled that as "amnesty" and urged Republicans to reject it. "And I put my hand against the glass so they can put their hands against the glass". "Permanently separated", Trump said at the event.
Trump's tweet, GOP aides said, could make the task of corralling votes for the bill significantly more hard, though House Republican leaders said negotiations would continue. A hard-line conservative bill failed Thursday, while a vote on a compromise measure was postponed until next week.
But Marr said it's unfair for Democrats to accuse Colyer of "colluding with the Trump administration" when they don't have "any sort of evidence". "Dems are just playing games, have no intention of doing anything to solve this decades old problem".
He acknowledged that passing the bill would be an "uphill fight". She says, "No child should ever have to cry like that for something that we can avoid".
The Justice Department has also asked a federal court in California to allow children to be detained longer and in facilities that don't require state licensing while they await immigration court proceedings.
Roger Marshall is returning from a visit to the Texas border saying that several hundred immigrant children detained in a center there are getting good care.
"Our trip out here probably raised more questions than it answered", said Pennsylvania Representative Brian Fitzpatrick, a Republican.