SAN FRANCISCO • Ms Lilian Merida-Galicia and her seven-year-old daughter were nabbed after crossing the United States-Mexico border in Arizona and separated by US officials in mid-May.

Since then, the 23-year-old Guatemalan has been trying to learn of her daughter's whereabouts, said her lawyer Michael Avenatti.

Ms Merida-Galicia, who is being held in California, is just one of many incarcerated immigrant mothers whose lawyers tell similar stories about chaotic situations in which the mothers do not know where their children have been taken or how to contact them.

Mr Efren Olivares, a lawyer with the Texas Civil Rights Project that represents 381 migrant parents, said they are struggling to navigate a labyrinthine process.

"It's very difficult to reunite children with their parents because these government agencies were not prepared, and they're not designed, for family separation," he said.

Although President Donald Trump abruptly reversed course on Wednesday following a wave of outrage at home and overseas, and abandoned his policy of separating children from parents who are caught for illegally crossing the US-Mexico border, the fate of the more than 2,300 children already separated from their parents is unknown.

The federal government and Congress scrambled on Friday to address the many unanswered questions raised by the hastily drafted executive order Mr Trump issued on Wednesday.

Seeking to counter criticism of his border policies, Mr Trump invited families of Americans killed by undocumented immigrants to tell their stories of being "permanently separated" from loved ones.

"These are the stories that Democrats and people that are weak on immigration, they don't want to discuss, they don't want to hear, they don't want to see, they don't want to talk about," he said at the White House on Friday.

He also urged Republican lawmakers to drop their efforts to pass comprehensive immigration legislation until after the November congressional elections, flip-flopping on his appeal earlier in the week for Congress to act soon.

"Elect more Republicans in November and we will pass the finest, fairest and most comprehensive Immigration Bills anywhere in the world," Mr Trump said on Twitter.

The House of Representatives on Thursday rejected a Bill backed by conservatives that would have halted the practice of splitting up families and addressed other immigration issues.

The House postponed until this week a vote on a more moderate Bill after it failed to attract enough support for passage. But Mr Trump's latest tweets could doom that effort.

REUTERS, AGENCE FRANCE-PRESSE, WASHINGTON POST