With temperatures plunging and no end in sight to an influx of migrants, city officials and advocates say conditions could get much worse for the newcomers.

More than 66,000 migrants currently reside in New York City shelters, according to officials. The number includes families with children, many of whom face the end of their 60-day shelter limit shortly after Christmas.

Meanwhile, border crossings are increasing dramatically, with Border Patrol agents making 17,500 arrests this past week.

Manuel Castro, commissioner for the mayor’s Office of Immigrant Affairs, Beatriz Ponce De León, deputy mayor of Immigrant, Migrant and Refugee Rights for Chicago, and Matt Griffith, interim executive director of the Office of Immigrant Affairs in San Diego.

“Whatever the federal government is doing, whatever the strategy it currently is, it’s not working,” Castro said. “And so, I’m glad that we’re all coming together as cities because we cannot do this alone. New York City cannot advocate alone.”