CHICAGO (AP) — Cardinal Blase Cupich of Chicago is telling principals at more than 200 archdiocese schools to prevent federal immigration officials from entering their buildings without a warrant.

In a letter sent to principals Monday, Cupich offered similar instructions to those issued to Chicago Public Schools principals last week. The guidance comes as the Trump administration has vowed to crack down on immigrants who are living in the U.S. illegally.

Cupich tells school officials to ask to review any warrants or other documents before allowing federal immigration agents inside and to contact archdiocese lawyers. He doesn’t say what to do if the agent insists on being allowed in.

The 76,000 student school system is one of the largest private school systems in the country. About a quarter of its students are Hispanic.