Del Rio Mayor Bruno Lozano said that hot temperatures and the fluctuating level of the Rio Grande could make the camp dangerous. The temperature in Del Rio has been in the high 90s and on Monday is forecast to hit 105 degrees.
Migrants have pitched tents and built makeshift shelters under the bridge while others bathe and wash clothing in the river. At least two women have given birth, one of whom later tested positive for COVID-19, said Val Verde County Judge Lewis Owens, the county's top elected official.
Haitian migrants must decide whether to stay put and risk being deported to the country they left or return to Mexico.
Some of those waiting in Mexico, like Charles Edirame, said they are afraid to return to Haiti after the recent devastating earthquake and the assassination of President Jovenel Moïse.
Edirame and his wife and daughter crossed the border to the encampment but returned to Mexico when they heard about the deportations. The Haitian family was deciding what to do next.
"We don't have money, we don't have anything. We spent two months getting here on foot," he said. "If I go back, I could die the next day."
"Let's go! Get out now! Back to Mexico!" agents shouted. One man stumbled and fell as he tried to dodge an agent.