Updated

Failure by the Biden administration to adequately address the crisis at the U.S.-Mexico border could result in far greater numbers of people trying to enter the U.S., an anti-corruption activist in Guatemala is warning, according to a report.

"You will have 1 million people at the border," activist Manfredo Marroquin, who met with Vice President Kamala Harris when she visited Central America earlier this year, told the Los Angeles Times in a story published Wednesday.

To get a sense of what that would mean, the recent incident that strained local resources in Del Rio, Texas, after large groups of people gathered under a bridge, involved about 15,000 migrants.

Marroquin argued that the "root causes" of migration, which Harris has pledged to tackle in her role as the Biden administration’s manager of the U.S. response to the migrant crisis, have only worsened since Harris’ June visit, according to the report.

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He called for greater engagement by the U.S. to address the problem, the Times reported.

Harris has identified one of the root causes of migration as government corruption in countries such as Guatemala, El Salvador and Honduras, whose citizens make up a large portion of the migrants who’ve been trying to enter the U.S. since the crisis began. 

Corruption fighter fired

But just six weeks after Harris visited Guatemala in June, the country’s attorney general fired the nation’s leading anti-corruption prosecutor, Juan Francisco Sandoval, who has since relocated to Washington, D.C., the Times reported.

Vice President Kamala Harris and Guatemalan President Alejandro Giammattei are seen at the National Palace in Guatemala City, June 7, 2021. (Associated Press)

Before he fled, Sandoval had gathered evidence allegedly implicating Guatemalan President Alejandro Giammattei in a bribery scheme, The New York Times reported. A new investigation of the country’s president has since gotten underway, the newspaper reported. 

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Giammattei has been among the Central American leaders with whom Harris has been negotiating in her efforts to address the migrant crisis. The vice president spoke with Giammattei by phone in March and then met with him in June during her visit.

Prior to Harris’ arrival in Guatemala, Giammattei had dismissed the "root causes" narrative, instead blaming Biden administration policies, differing from those of the Trump administration, for drawing people northward.

"The message changed to, ‘We’re going to reunite families, we’re going to reunite children," Giammattei told CBS News at the time. "The very next day, the coyotes were here organizing groups of children to take them to the United States."

No long-term goal?

Eric L. Olson, an expert on Central America, told the Los Angeles Times he’s worried that the Biden administration’s inability to make headway on the root causes, coupled with political pressure from critics, could lead to the Biden White House ultimately giving up on the issue.

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"We don’t have a long-term goal," Olson argued. "We’re constantly solving problems and then we walk away when we think we solved the problems, or we get bored with the region and we walk away."

In the near term, Harris is spearheading a plan that calls for $4 billion in U.S. tax dollars to help pay for social and economic programs in Guatemala, El Salvador and Honduras that are aimed at convincing those countries’ citizens to stay in their native countries rather than try to enter the U.S., the L.A. Times reported.

Harris also has been seeking donations for the program from Ireland, Finland, Japan and South Korea, the report said.

Fox News' Adam Shaw contributed to this story.