With Kamala Harris visiting Guatemala and Mexico on her first foreign trip as vice president, the Biden administration is expected to announce new measures to fight smuggling and trafficking, and hopes to announce additional anti-corruption efforts as well on Monday, a senior administration official said.

The official, who briefed reporters traveling with Harris on Sunday, spoke on condition of anonymity to preview announcements before they have been made public. No further details were provided.

Harris has been tasked by President Joe Biden with addressing the root causes of the spike in migration to the U.S.-Mexico border, and her aides say corruption will be a central focus of her meetings with Guatemalan President Alejandro Giammattei on Monday and Mexico’s Andres Manuel Lopez Obrador on Tuesday.

“Corruption really does sap the the wealth of any country, and in Central America is at a scale where it is a large percentage of GDP across the region,” said special envoy Ricardo Zuniga.

“We see corruption as one of the most important root causes to be dealt with,” Zuniga added.

The trip got off to a rocky start when Harris’ plane returned to Joint Base Andrews in Maryland about 30 minutes after takeoff because of what her spokesperson said was a problem with the landing gear. She departed on another plane and landed late Sunday in in Guatemala City, where she was met by Foreign Minister Pedro Brolo.

Harris is seeking to secure commitments from Guatemala and Mexico for greater cooperation on border security and economic investment, and aides say she will also discuss vaccine sharing during her meetings. But corruption in the region — a far more intractable challenge — will complicate her efforts.

It’s already had a significant impact on her work in Central America. Harris has yet to engage substantively with the leaders of Honduras and El Salvador, who are both embroiled in corruption scandals.

Giammattei has faced criticism over corruption within his own government. Zuniga acknowledged that the U.S. government faces a challenge in working with him but argued Harris was in the country in part to have a direct conversation with the president about this and other issues.

“The best way to deal with these cases where you have a very complex relationship in a country like Guatemala is to talk clearly and plainly as partners, as countries that have to get along” he said.

Harris has laid out an approach centered on creating better opportunities and living conditions in the region through humanitarian and economic aid. She announced plans to send $310 million to provide support for refugees and address food shortages, and recently secured commitments from a dozen companies and organizations to invest in the Northern Triangle countries to promote economic opportunity and job training.

Washington won some goodwill through its vaccine diplomacy this past week. Giammattei and López Obrador both received calls from Harris on Thursday telling them the U.S. would be sending 500,000 doses and 1 million doses, respectively, of COVID-19 vaccine.

While in Guatemala, Harris also plans to meet community leaders, innovators and entrepreneurs. In Mexico, she will speak with female entrepreneurs and hold a roundtable with labor workers.

She’s underscored the need to address corruption in public remarks and events. In a May meeting with a number of leading voices on Guatemala’s justice system, she noted her work as a prosecutor and said that “injustice is a root cause of migration.”

“Part of giving people hope is having a very specific commitment to rooting out corruption in the region,” she said.

Harris has also raised the issue during virtual meetings with the leaders of both countries, and aides say she will do it again during meetings on her trip. During their past conversations, they have discussed areas of mutual interest — improving port security, combatting smuggling networks, going after corrupt actors — and the goal of this trip is to turn that talk into action, aides say.

While the vice president will make announcements concerning new efforts at cooperation and new programs, she’s not expected to announce any new aid during her trip.