The U.N. children's agency says the Trump administration policy of separating migrant children from their families is "not right," citing "heartbreaking" cases where even some babies are taken from their parents.

UNICEF says immigration enforcement and protection of children's rights is "not a zero-sum game."

Henrietta Fore, an American who has headed UNICEF since earlier this year, said separation of families and detention are "traumatic experiences" for children that can leave them more vulnerable to abuse.

In a statement from her read Tuesday by UNICEF spokesman Christophe Boulierac, Fore noted the U.S. government has long supported UNICEF's efforts to help migrant children in places like Syria, South Sudan and Haiti.