MEXICALI, Mexico (AP) — About 175 people in a caravan of Central American asylum-seekers are on the final leg of a monthlong journey to the United States, with the Trump administration warning they could be detained and quickly deported.

The migrants in the Mexico border city of Mexicali are preparing for a bus trip to Tijuana to link up with about 175 others who have already arrived in preparation for a weekend attempt to cross into San Diego.

Lawyers plan free workshops on the U.S. immigration system for the migrants ahead of their planned attempt on Sunday to seek asylum in the U.S.

Organizer Leonard Olsen of the Pueblos Sin Fronteras group says many migrants in Mexicali were tired from their lengthy journey from southern Mexico and nervous about the possibility of being detained.