US immigration authorities arrested 64,000 migrants at the southern border in August - approximately 22% fewer people than July, and a 60% decrease from the 130,000 apprehensions in May, according to a Monday statement by Customs and Border Protection (CBP) Commissioner Mark Morgan.

Perhaps immigrants are rethinking an uncertain future in an ICE detention center after a sweltering trek through Mexico?

"The president has made it very clear that he’s going to use every tool available to him and this administration to address this unprecedented crisis at the southern border," said Morgan during a White House briefing.

As The Hill notes, while border crossings tend to decrease during the hot summer months, this year's precipitous drop is significant.

Trump threatened in June to impose tariffs on Mexican goods if the country did not take stronger actions to curb the flow of migrants headed for the U.S. border. Trump backed off the tariffs after Mexico said it would do more to address immigration. In the months since, Trump has often praised Mexico for its enforcement measures, and Morgan said Monday that the Mexican government has apprehended roughly 134,000 people so far this year, up from 83,000 in all of 2018.

"The government of Mexico has taken meaningful and unprecedented steps to help curb the flow of illegal immigration to our border," said Trump, who has made immigration a central issue to his administration - wall or not. Moreover, Trump has attempted to limit asylum claims while pressuring other countries to take in more migrants.

“In 22 years of patrolling our Southern Border, I have never seen Mexico act like a true Border Security Partner until President Trump got involved, and now they are stepping up to the plate and doing what they need to do.” Brandon Judd, National Border Patrol — Donald J. Trump (@realDonaldTrump) September 7, 2019

And as Politico notes, "The decline in border traffic — if sustained — could amount to a major victory for Trump as he heads into the 2020 election," adding "Perhaps more important, the experimental measures taken by his administration could reshape immigration enforcement for years to come."

"I think that they are getting exactly what they said they would get, by forcing the hand of Mexico," said pro-migrant group Alianza Americas executive director, Oscar Chacón, who added "But the question is, 'Is it sustainable?'"

"People know that if they come into Mexico, they have to respect the Mexican law," said Mexican Ambassador to the US, Martha Bárcena in a statement to Politico, adding that migrants looking to enter the US now realize that it's "not as easy as they were told it was going to be."

On Tuesday, Secretary of State Mike Pompeo and Vice President Mike Pence will meet in Washington with Mexcian Foreign Affairs Secretary Marcelo Ebrard along with other officials to discuss the immigration strategy between the two countries, according to Mexican officials.

Mexico’s delegation will press the U.S. to process asylum cases faster, as migrants from Central America and elsewhere pile up in Mexican border towns. It will also push for increased aid to Central America and efforts to stop the flow of guns from the U.S. to Mexico. The Mexico agreement followed threats from Trump to impose across-the-board escalating tariffs on Mexican goods that would likely have resulted in severe economic costs on both sides of the border. When the agreement was announced, it was widely interpreted as a fig leaf that would allow Trump to back down but wouldn’t likely have much impact on migration. But the deal's components appear to have contributed to the steep drop in border arrests, according to interviews with six former officials and advocates both for and against greater levels of immigration, as well as a POLITICO analysis of enforcement data. -Politico

The deal between the US and Mexico is centered around two main goals; heightened enforcement by Mexico - which yielded a three-fold y/y increase in arrests in June of 32,000 migrants, and an expansion of the "remain in Mexico" program - a.k.a. the Migrant Protection Protocols.

Mexico's National Guard, meanwhile, has established a stronghold along their southern border with Guatemala - including key migrant crossing points in the city of Ciudad Hidalgo in the Mexican state of Chiapas. 6,000 troops have been committed to the anti-migration effort.

"They really have made it harder to cross where people were crossing before," said Andrew Selee, president of the non-partisan Migration Policy Institute, who called Mexico's actions an "all-out enforcement effort like we've never seen before," according to Politico.

Mexican officials have also stepped up enforcement in the city of Tapachula - roughly 45 minutes north of Ciudad Hidalgo.

"Particularly in the area around the Suchiate River at the Ciudad Hidalgo crossing, it seems like it is almost impossible to cross in a balsa boat as an undocumented migrant and not get detained by a National Guard agent," according to Maureen Meyer - director for Mexico and migrant rights with the Washington Office on Latin America.

"Leaving the Tapachula area has also become more complicated given enforcement at different checkpoints in the highways around the city."