Why is the US separating migrant children from their families?

There's a big argument going on in America about the way some migrant children are being split up from their families.

It's part of a crackdown by Donald Trump's government on people who are trying to get into America from Mexico illegally.

Over a recent six-week period, nearly 2,000 children have been separated from their families over when their parents are held by border guards.

In many cases, the families have been reunited but there are reports of people being kept apart for weeks and even months.