Former President Barack Obama criticized President Donald Trump’s policy of zero-tolerance towards illegal immigrants crossing the U.S.-Mexico border, in a lengthy Facebook post Tuesday.

Obama’s post was written in the context of World Refugee Day: “To watch those families broken apart in real time puts to us a very simple question: are we a nation that accepts the cruelty of ripping children from their parents’ arms, or are we a nation that values families, and works to keep them together? Do we look away, or do we choose to see something of ourselves and our children?”

The Trump administration issued its own World Refugee Day message, saying, “The United States provides more humanitarian assistance than any other single country worldwide, including to refugees.”

Trump’s policy of criminally prosecuting illegal immigrants at the U.S.-Mexico border results in the separation of families because of a court settlement in 1997. Families must be separated because of the court settlement, which does not allow children to be held in adult prisons.

Obama himself separated many families at the U.S.-Mexico border, though he prosecuted illegal immigrants at a much lower rate. Department of Homeland Security data shared with The Daily Caller earlier shows his administration prosecuted nearly 500,000 illegal immigrants between 2010 and 2016.

Department of Health and Human services data similarly shows that nearly 200,000 children were referred to detention facilities between 2012 and 2016, though there is no way to parse whether they arrived unaccompanied or were separated from families.

The Trump administration is considering executive action to detain families together while prosecuting all people who illegally cross the U.S.-Mexico border.