President Donald Trump's administration will reinstate the family ban on migrants with children, the president's senior border adviser, Tom Homan, said today.

Homan said the administration intends to build family detention facilities.

"You knew you were in the country illegally and chose to have a child. So you put the family in that position. We're going to have to build family facilities. How many beds we need will depend on what the data says," Homan told the Washington Post.

Under the Trump administration, he said families detained together would be deported together. However, he acknowledged that the government cannot remove children who are US citizens. The policy gives parents a choice to decide whether to separate the family, he added.