– After days of walking from Mexico's southern border, the caravan of hundreds of migrants that has drawn President Donald Trump's Twitter ire has now halted on a brown-grass soccer field, its participants unsure and anxious about the way forward.

The men and woman, most from Central America, were squatting Tuesday in a walled public park while government officials decide their fate.

"We are scared, just like you," Irineo Mujica, the head coordinator of the migrant caravan, told the assembled group through a megaphone on Tuesday morning

Trump has made the migrant caravan a central theme in his tweets for three days running. The president has warned that Mexico must stop the group or risk being penalized in the negotiations over reforming NAFTA. He has also threatened to reduce foreign aid to Honduras, the country of origin of many marchers.

Trump's comments have turned what had been an annual march to raise awareness about the suffering of migrants into something of a political crisis for Mexico. On Monday, Mexican immigration officials began to register the hundreds of migrants and talked about the possibility of humanitarian visas for the most vulnerable, while others might receive permits of less than a month. Some have already been deported, according to Mexican officials.

While the march wasn't unprecedented, this year's exercise drew an unusually large number of participants. Conservative American media jumped on the reports, depicting it as a sign of the threat of illegal migration to the United States. In fact, U.S. border authorities reported a 26 percent decline in the number of people detained or stopped at the southern border in 2017 compared to the prior year.

On Tuesday, Trump said he would call out the military to guard the border.

"We cannot have people flowing into our country illegally," Trump said, as he discussed the caravan while posing for a photo at the White House with Baltic state leaders.

Earlier in the day, he tweeted: "The big Caravan of People from Honduras, now coming across Mexico and heading to our "Weak Laws" Border, had better be stopped before it gets there. Cash cow NAFTA is in play, as is foreign aid to Honduras and the countries that allow this to happen. Congress MUST ACT NOW!"

At the Victor E. Flores Morales sports park in this southern city in Oaxaca state, scores of children played Tuesday on slides and metal swings, waiting for their parents and the organizers of this caravan to decide the next move. For most migrants, their goal is the United States, still more than 800 miles away. They wanted to march on.

Some said they heard about this caravan through friends and relatives; others said they have made the trip in the past but weren't allowed into the United States. The migrants said they had convened from several countries in Tapachula, a city along Mexico's southern border, and begun their march north. A number of them said they were fleeing gang violence and extortion threats in their violence-plagued countries, while others said they were looking for better paying jobs.

After several nights of sleeping outdoors, the migrants had begun adapting to this bivouacked lifestyle. A former Pizza Hut employee from Guatemala boiled fish soup for the camp over a wood fire alongside his new friend, a fajita cook from El Salvador who had been deported after living in Texas for 14 years. On the surrounding streets, migrants begged for money.

All of those interviewed on Tuesday said that they would prefer to live in the United States but they would settle for Mexico if that was where they were allowed to stay. Almost anything, they said, would be better than returning to Central America, which has some of the hemisphere's highest incidences of violence.

"There is a barbarous situation in our country," said Santos Alberto Lino, 40, who had worked as an auto mechanic in Honduras before joining the caravan. "People want to live in peace and harmony."

Trump's tweets have turned into fodder for the four candidates competing in the July 1 presidential election, with Mexican politicians rejecting his criticism of the country's response to the caravan. But the Trump messages have caused a colossal headache for the Mexican government as it attempts to secure a NAFTA deal before the vote.

Mexican officials responded this week to Trump's tweets as they usually do: politely, preferring not to inflame tensions with their northern neighbor. Mexico's chief technical negotiator on the trade deal, Kenneth Smith Ramos, tweeted on Tuesday that the process of modernizing the treaty "is entering a phase of intense activity." Mexico, he added, "will continue working in a constructive manner."

The low-key Mexican government response to Trump left the sense for some that the administration of President Enrique Peña Nieto had caved.

Esteban Illades, editor of the Mexican magazine Nexos, said that the government "will definitely feel pressured to cave into Trump's demands."

In southern Mexico, many of the members of the migrant caravan knew that Trump had spoken harshly about them.

"Donald Trump's words are hurtful to us," said Manuel Flores, 30, a Guatemalan who cooks at the camp. "We are not extraterrestrials, we are not from another world."

His friend, Jose Ernesto, 28, from El Salvador, spoke about his time working in a Texas grillhouse for years before his deportation.

"You look in the kitchen and who prepared that food for you? It's a Mexican, it's a Hispanic," Ernesto said. "We are the ones who have made your country the way it is."