The Trump administration plans to reunify less than half of the immigrant children under age 5 who were separated from their parents under Donald Trump's "zero tolerance" policy before a court-mandated deadline.

Federal officials said in court records filed Tuesday that they would reunite only 38 of the 102 children separated from their parents by that day’s deadline, with another 16 following shortly.

US District Court Judge Dana Sabraw ordered the administration two weeks ago to reunite all of the children under age 5 with their families by Tuesday night. The government had previously said it would reunite 54 children with their parents by that deadline.

But the administration now says that 27 of those children are not eligible to be reunited with their parents, and another 20 cannot be reunited by the deadline because of “logistical impediments”. Another child has a parent whose criminal background check results are still in question, the government said in a press release.

Asked about his administration's failure to meet the deadline at a press gaggle, Mr Trump responded: "Well, I have a solution. Tell people not to come to our country illegally."

‘Families belong together’ protests over Trump immigration policy Show all 8 1 /8 ‘Families belong together’ protests over Trump immigration policy ‘Families belong together’ protests over Trump immigration policy Mishawaka, Indiana AP ‘Families belong together’ protests over Trump immigration policy Washington DC AFP/Getty Images ‘Families belong together’ protests over Trump immigration policy New York Mayor Bill De Blasio speaks in Tornillo, Texas alongside the many other US mayors who have called for detained immigrant children to be reunited with their families AP ‘Families belong together’ protests over Trump immigration policy Albuquerque Mayor Tim Kelle leaves a teddy bear as a gift for detained immigrant children in Tornillo, Texas AP ‘Families belong together’ protests over Trump immigration policy Seattle Mayor Jenny Durkan and Los Angeles Mayor Eric Garcetti leave sandals as gifts for detained immigrant children in Tornillo, Texas AP ‘Families belong together’ protests over Trump immigration policy San Diego, California EPA ‘Families belong together’ protests over Trump immigration policy US embassy, Mexico City AFP/Getty Images ‘Families belong together’ protests over Trump immigration policy San Diego, California EPA

Mr Sabraw has also ordered all of children separated under Mr Trump's “zero tolerance” policy to be reunited by the end of July. That number that likely tops 2,000, according to government figures.

Mr Sabraw did not back down from the deadlines in a court hearing on Tuesday, warning the administration that these were firm requirements and not “aspirational goals”. He ordered the administration to reunite 63 of the children with their families by that night or face penalties.

Thousands of migrant parents and children were separated at the US-Mexico border between early May and mid-June under Mr Trump’s “zero tolerance policy,” which required anyone caught crossing the border illegally to be referred to prosecution.

Mr Trump ordered the end of family separations last month, under immense public pressure, but the process of reunification has been halting.

Lee Gelernt, an attorney with the ACLU, which filed the lawsuit, said on Monday that the administration’s failure to comply with the court order was “disappointing”.

“The court is holding the Trump administration’s feet to the fire to get these kids reunited with their parents. That’s the most important thing,” he said.