United States President Donald Trump has erected a “legal wall” that will make things more difficult for the thousands of Central American migrants heading for the Mexico-U.S. border, a migrants’ advocate says.

Eunice Rendón of advocacy group Agenda Migrante said a proclamation signed by Trump today, requiring migrants to cross the border legally if they wish to apply for asylum, means they will have to demonstrate “credible fear” that they would suffer violence should they return to their home countries.

They will have to present a good argument, she said, indicating that she and fellow attorney Janet Moreno of the America Immigration Lawyers Association offered legal council to the approximately 5,000 migrants who are currently camping out in a sports stadium in Mexico City.

Meanwhile, as many as 2,000 left this morning to resume their journey north. By mid-afternoon they were beginning to arrive in Querétaro.

Those who remain in the capital had hoped for bus transportation to the northern border courtesy of the United Nations, but their hopes were dashed today.

UN officials declined the request at a two-hour meeting with representatives of the migrant caravan.

The latter responded by warning they would hold the international body responsible for any aggression committed against members of the caravan on their journey north, and asked that its representatives refrain from traveling with them.

They also said they had requested a meeting with president-elect López Obrador but he “roundly refused.”

The caravan plans to leave Mexico City Saturday morning for Querétaro, where they will decide which route to follow to the border, choosing between Tijuana and Nuevo León.

The caravan is the first to have arrived in Mexico via the southern border, which it began crossing October 19.

Source: El Financiero (sp), Milenio (sp)