Throughout the week, federal police aircraft arrived in the city of Tapachula, near the border with Guatemala, with hundreds of federal officers equipped with antiriot gear.
President Donald Trump has threatened to call in the military to seal off the US" southern border with Mexico, unless the Mexico takes action to halt a "caravan' of migrants making its way to the USA from Central America.
Images like this caught Trump's eye Thursday morning, and he started leveling a slew of threats - including cutting off aid to Central American countries and demanding Mexico intervene.
Several thousand Honduran migrants moved this week through Guatemala, and some were trying to cross to Mexico on Thursday, according to local media.
Mexico's government has said only migrants with the proper papers will be allowed entry into the country, although anyone wishing to seek asylum was free to do so.
Pompeo's trip to Mexico was planned before the caravan, but Pompeo and other USA officials have said that it will inform his conversations with Mexican officials on Friday.
"The assault on our country at our Southern Border, including the Criminal elements and DRUGS pouring in, is far more important to me, as President, than Trade or the [United States-Mexico-Canada Agreement]", Trump wrote.
Officials in Mexico have said the 4,000 or so Hondurans will not be allowed to enter the country as a group and must have a passport or visa - or apply for refugee status. Saturday will mark a week on the march for the throng of hopefuls who plan to assemble on the U.S. -Mexico border and demand entry.
Trump hails body slamming Congressman Greg Gianforte in Montana
The next day, Mr Gianforte won a special election for Montana's US House seat. "But I had heard he body slammed a reporter ". He was ordered to pay $385 (£304), complete 40 hours of community service and 20 hours of anger management counselling.
The issue with Trump's threat is that deploying active usa military troops for domestic law enforcement duties is illegal, unless he declares a national emergency and is granted a waiver by Congress.
US Secretary of State Mike Pompeo is due in Mexico City on Friday.
"Anyone who wants to work in our country ... will have a work visa", he said. The US no longer has to house them until their cases are heard.
"They wanted that caravan and there are those that say that caravan didn't just happen", Mr. Trump said.
Trump, who campaigned for president with vows to stop illegal immigration, said on Twitter today that he thinks Republican candidates for Congress should campaign on the issue in the upcoming midterm elections.
The countdown is on for the arrival of what has come to be known as the "Honduran caravan" - an estimated 4,000 men, women, children and infants who left the troubled Honduran city of Pedro Sula last weekend on foot and by truck.
Mexico's main reaction has been to step up security on its southern border with Guatemala. The foreign minister, Luis Videgaray, asked the United Nations to assist with what could be a crush of requests.
Guatemalan President Jimmy Morales said on Wednesday his government dismissed threatened constraints placed on foreign aid.
"It was predictable, and it's also very close to the election".