(CNN) Parents and children who together try to enter the United States illegally will no longer be separated at Mexican border .

But it's not clear when -- or if -- at least 2,300 children taken from their parents under the prior policy will be reunited. Neither is the long-term plan for families who are detained jointly.

Here's what we know:

Will the detentions continue?

It appears the "zero tolerance" policy has been curtailed, at least for the moment, based on emails obtained by CNN. According to the emails from Wednesday night and Thursday morning, Customs and Border Protection has told its field offices to suspend referrals for prosecution for parents who cross the border illegally with children. The apparent change, which can be reversed, further illustrates the confusion over how to implement the executive order signed Wednesday by President Trump intended to halt family separations at the border.

The executive order signed Wednesday by President Donald Trump replaces family separation with family detention.

The executive order seeks more authority to detain families together until the end of their immigration proceedings.

It states that it is the policy of the administration "to maintain family unity," a new position from the administration's previous defense of separating families, when it said those affected had put themselves in that position by crossing the border illegally.

Trump's order asks that families be housed together "where appropriate and consistent with law and available resources."

Will the separated children be reunited?

The short answer is: It's too early to tell.

So far, the administration has not provided details on how it plans to unite the at least 2,300 children separated from their families.

Those separated children have been designated as "unaccompanied alien children" and are in facilities or foster homes spread across states far from the US-Mexico border, including Michigan, New York, South Carolina and more.

The executive order does not address the uniting of families already separated -- and existing policies place the onus on parents to find their children in Department of Health and Human Services custody and seek to reunite with them.

"For the minors currently in the unaccompanied alien children program, the sponsorship process will proceed as usual," HHS spokesman Kenneth Wolfe said Wednesday.

In that program, children typically are connected with friends, relatives or other suitable volunteers to care for them, but in most cases, the children were alone when they entered the US illegally. And once a parent is in an adult detention facility, it is unlikely HHS can release their child back to them, as they would not qualify as a sponsor.

Later Wednesday, the HHS' families division's spokesman said Wolfe "misspoke." But he didn't provide details on any plans to unite separated families.

"It is still very early and we are awaiting further guidance on the matter," Brian Marriott said.

"Our focus is on continuing to provide quality services and care to the minors in HHS/ORR (Office of Refugee Resettlement) funded facilities and reunifying minors with a relative or appropriate sponsor as we have done since HHS inherited the program."

A former director of US Immigration and Customs Enforcement, said he was "really shocked" to see that the executive order did not address the issue.

"I thought the whole point of this was to reunite the kids," John Sandweg said.

What about children who hadn't gotten to HHS sites?

Before getting transferred to HHS oversight, US Customs and Border Protection, which operations mainly along the border, can hold children for as long as 72 hours.

Children still in CBP custody when Trump's executive order went into effect now will stay there until their parents return from court proceedings , then be detained with them, an announcement made Thursday by the border agency implies.

"For those children still in Border Patrol custody, we are reuniting them with parents or legal guardians returned to Border Patrol custody following prosecution," a CBP spokesperson said in the statement.

Who will detain the families?

Unlike in the past, adults will not be turned over to the Justice Department when they face criminal charges.

Instead, they'll be under the custody of the Department of Homeland Security, a change the administration had previously said it could not make.

The order maintains an exception for when a child is at risk or there is concern the parent would pose a risk to the child's welfare.

There's also a catch that says the families will be detained to the "extent permitted by law and subject to the availability of appropriations" -- again something that remains to be worked out.

Where will the families be held?

The order instructs federal agencies -- notably the Defense Department -- to prepare facilities to house the potentially thousands of families who will be detained. It is unknown how the agencies will proceed now that the zero tolerance policy has been effectively neutered.

There are now far more beds for single adults than for families. With thousands of families apprehended crossing the border illegally on average each month, detaining them could rapidly tax government resources.

"The secretary of defense shall take all legally available measures to provide ... existing facilities available for the housing and care of alien families, and shall construct such facilities if necessary and consistent with law," Trump's executive order states.

The military would have no responsibility for any of the activities, defense officials say. Officials compared it with being a "landlord" but not responsible for the management of the housing, security, food services or other activities.

When will their cases be heard in court?

In the executive order, Trump makes an effort to have families' cases decided faster in immigration courts.

Until now, if a family had a potentially valid claim of asylum, it could wait months or years for an immigration court hearing, during which time they could live and work in the United States.

To expedite the process for deporting a family or granting its members legal status, Trump ordered the Justice Department to "prioritize" cases "involving detained families" -- presumably allowing them to jump the immigration court line.

CORRECTION: This story has been updated to make clear that the executive order does not address the uniting of families.