San Francisco is suing the Trump administration over its crackdown on cities with sanctuary policies that prohibit local law enforcement from aiding U.S. Immigration and Customs Enforcement (ICE) in arresting undocumented immigrants.

Some local officials are pushing back against the federal government’s assertion that they must help ICE with its deportation campaign.

San Francisco leaders reaffirmed its status as a sanctuary city on Tuesday as the Trump administration vows to make good on campaign promises for increased immigration enforcement.