The executive order would work around an existing consent decree, called the Flores settlement, that prohibits children from being kept in immigration detention, even with their parents, for more than 20 days, according to the report.
Trump, addressing what his administration has characterised as an unwanted side effect of his zero-tolerance policy on illegal immigration, signed the order to keep families who illegally cross the U.S. southern border together as they await immigration proceedings.
"We have to get the Democrats to go ahead and work with us because as a result of Democrat-supported loopholes in our federal laws, most illegal immigrant families and minors from Central America who arrive unlawfully at the border can not be detained together or removed together - only released", he said.
The legislation would halt the separation of immigrant families by preventing the U.S. Department of Homeland Security from taking children from their parents at the border.
Before departing for Minnesota, Trump signed an executive order to keep families together at the border.
After long insisting that Congress alone could solve the problem, the Republican president seemed ready to take the matter into his own hands. I consider it to be a very important executive order.
The order, which Trump signed Wednesday, directs the Department of Homeland Security to keep families intact when they are caught crossing the border.
US Customs and Border Protection said on Tuesday that 2,342 children had been separated from their parents at the border between May 5 and June 9.
Sen. Pat Roberts, R-Kansas, one of 13 Senate Republicans who signed a letter urging Trump to end his administration's separation policy, was also waiting on the yet unknown details. "We are going to keep the families together".
He said he was looking into whether the court could block deportation of parents until they have been reunited with their children, and whether it could force the Trump administration to reunite those separated. Expanded facilities could be key, as migrant children separated from their parents are now housed by a different department, Health and Human Services.
Michigan's Department of Civil Rights says immigrant children as young as three months of age have arrived in the state for temporary foster care placement after being separated from their parents at the USA border.
Meanwhile, any children entering the country with them, including infants, would be taken away and held separately.
The pope said he stood with USA bishops who had denounced the action as "immoral", and denounced anti-immigrant action in both the U.S. and Europe, saying that "I believe that you can not reject people who arrive".
He reminded Americans that almost everyone in this country comes from somewhere else, and that those who were born into citizenship here should recognize how fortunate they are.
Two people close to Nielsen said she was the driving force behind the turnabout that led to the new order keeping families together.
Obama argued that "to find a way to welcome the refugee and the immigrant - to be big enough and wise enough to uphold our laws and honor our values at the same time - is part of what makes us American".
As Trump left the session, a half-dozen House Democrats confronted him and yelled, "Stop separating our families!"
Stories of weeping children torn from the arms of their frightened parents have flooded the media and the policy has been widely criticized by church groups, politicians and children's advocates who say it is inhumane.