Updated 9:57 p.m. ETA group of roughly 200 people traveling from Central America, arrived at the U.S.-Mexico border Sunday seeking political asylum and were greeted by supporters across a border fence in the U.S. holding welcome signs. But upon the group's arrival, U.S. immigration officials announced that the port of entry in San Diego County had reached capacity. Officials had warned that the crossing might fill up as its capacity is just around 300 people, according to the Associated Press. "At this time, we have reached capacity at the San Ysidro port of entry for CBP officers to be able to bring additional persons traveling without appropriate entry documentation into the port of entry for processing," Commissioner Kevin McAleenan said in a statement. "Those individuals may need to wait in Mexico as CBP officers work to process those already within our facilities."Despite the news that the crossing was full NPR's Carrie Khan reports that members of the caravan were not immediately deterred — still forming lines and hoping to march toward the crossing.If migrants approach the crossing and are turned away they would have to stay in Mexico — a decision that others had already made.The migrants are facing an uncertain future wherever they land. Many have decided not to seek to asylum in the U.S. after speaking with volunteer immigration lawyers, who have advised the migrants to be prepared for separation.The weeks-long trek by this so-called caravan is an annual, organized trip. Most of the people are from Honduras and are fleeing the violence that erupted after the highly contested presidential elections in November. Many people are also from Guatemala and El Salvador, where gang violence is prolific.This year's journey, however has been the target of harsh political rhetoric and ire from President Trump. He points to the group of migrants as justification for increased security, namely a border wall.Trump has also called on the Mexican government to stop the caravan before it reaches the border. The demands come amid increased tension between the two countries as they seek to hammer out a revised North American Free Trade Agreement. Trump has gone as far as to threaten NAFTA, calling it Mexico's "cash cow," if the country did not act to slow traveling migrants.A number of migrants seeking asylum Sunday decided to change course along their journey, so much so that it momentarily stalled the trip. Central Americans face an uphill battle when seeking asylum in the U.S. NPR's Eyder Peralta reports that in 2010, 9 out of 10 Hondurans and Salvadorans are denied asylum, as well as 8 out of 10 Guatemalans.The Department of Homeland's Security says it is monitoring the situation, and encourages the migrants to seek shelter from violence in the first safe country they encounter, including Mexico.In a statement, Secretary of Homeland Security Kirstjen Nielsen said: