US Vice President Kamala Harris has urged would-be migrants in Guatemala not to try to enter the United States illegally.
Speaking on her first overseas trip since taking office, she said the journey north was dangerous and would mainly benefit people smugglers.
Ms Harris warned people they would be turned back at the border.
She has been tasked by President Joe Biden with controlling a surge in migration at the southern border.
Ms Harris has described her task as finding solutions to tackle the root causes of the border crisis, including corruption and the lack of economic opportunities. Her staff say this first visit is primarily an information-gathering trip.
In a news conference alongside Guatemalan President Alejandro Giammattei, she warned against illegal migration to the US, saying: "Do not come. Do not come. The United States will continue to enforce our laws and secure our borders."
She added: "If you come to our border, you will be turned back."
Ms Harris said she wanted the US and Guatemala to "work together" to find solutions to "long-standing problems".
She said people must be given a "sense of hope that help is on the way".
"It must be coupled with relationships of trust. It must be coupled with tangible outcomes, in terms of what we do as leaders to convince people that there is a reason to be hopeful about their future and the future of their children," Ms Harris added.
President Giammattei defended his government's own record of fighting corruption and said the fight against drug trafficking should be an key part of tackling the issue.
He announced a new processing centre for migrants who had been sent back from the US and Mexico and said that the focus for both countries should be on creating prosperity.
Ms Harris said the US would send 500,000 coronavirus vaccines to Guatemala and provide $26m (£18.3m) to fight the pandemic there. The region has been hard hit by the virus, further worsening living conditions.
She also met civil society leaders and entrepreneurs in the country before travelling on to Mexico where she will hold talks with President Andres Manuel Lopez Obrador on Tuesday.
President Biden has been criticised by Republicans who accuse him of ignoring the crisis on the southern border.
But in a recent speech to Congress, he said: "When I was vice president, I focused on providing the help needed to address these root causes of migration. It helped keep people in their own countries instead of being forced to leave. Our plan worked."
What are the key items on Ms Harris's agenda?
The border
More than 178,000 migrants arrived at the border this April, the highest one-month total in more than two decades, according to US border officials.
Of those migrants, more than 40% originated from the Central American region known as the Northern Triangle: Guatemala, Honduras and El Salvador.
This will be the main focus of Ms Harris' trip.
Corruption
A central issue contributing to the border crisis is the corruption of government officials in the region, who have been accused of aiding in drug and human trafficking.
Ms Harris will to discuss the situations in Guatemala and Mexico. But the vice-president has yet to speak to the leaders of Honduras and El Salvador.
"We have the capacity to give people hope," Ms Harris said last month. "Part of giving people hope is having a very specific commitment to rooting out corruption in the region."
Economic growth
Many migrants leaving the Northern Triangle say they are fleeing violence, discrimination and poverty.
The steady "brain drain" of locals has exacerbated problems caused by decades of political instability.
These countries have also stressed that they are feeling the most adverse effects of global warming - most notably hurricanes - despite hardly contributing to climate change.
Ms Harris said in her press conference in Guatemala that "we are doing the work of requiring certain progress be made" in order to attract US investment to the region.
She also pledged US investments towards agriculture, entrepreneurship and affordable housing, as well as for "a young women's empowerment initiative to increase education and opportunities for girls and women".
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