Migrant children at the United States border have the right to be with their family, UNICEF says.
More than 2000 children have now been separated from their families in a crackdown on illegal immigration at the US-Mexico border.
- White House officials cite the bible in defence of border seperation policy
- Trump murals overcrowding in Texas shelter for detained child migrants
- Mexico upset Trump called immigrants animals
UNICEF executive director Henrietta Fore says the situation is heartbreaking.
"Children - no matter where they come from or what their migration status - are children first and foremost.
"Those who were left with no option but to flee their homes have the right to be protected, access essential services, and be with their families just like all children."
Detention and family separation are traumatic experiences which can leave children more vulnerable to exploitation and abuse, she says.
"Such practices are in no one's best interests, least of all the children who most suffer their effects.
"The welfare of children is the most important consideration."
Ms Fore hopes refugees and migrant children's best interests will be paramount when the US Government decides what will happen to asylum seekers.