The Trump administration is threatening to withhold or redirect federal funding to New York’s mass transit system if it doesn’t receive documentation of the steps taken to address crime and create a safe environment for riders and workers.

On Tuesday, the Trump administration threatened to revoke MTA funding unless the agency provided a detailed list of its efforts to improve transit safety. Crime continues to trend down throughout the system.

In a letter to MTA Chair Janno Lieber, U.S. Transportation Secretary Sean Duffy demanded a list of “actions and plans to reduce crime on its system,” including rates of assaults, fare evasion and train surfing in the subway.