Donald Trump has made immigration and the U.S.-Mexico border a key campaign issue, successfully pressuring Republicans to reject a major bipartisan border deal earlier this year.

Kamala Harris, meanwhile, has sought to counter Trump's attacks on her immigration record during her campaign.

Trump's attacks come after President Joe Biden tapped Harris to oversee diplomatic efforts in Central America in 2021. While she focused on long-term solutions, the Department of Homeland Security remained responsible for overseeing border security.

Here's a look at what both candidates have promised on the issue:

Trump

In an editorial in January, Trump promised to use the Alien Enemies Act to remove known or suspected gang members, drug dealers or cartel members from the United States.

In a video posted to Truth Social in February before a visit to the border, Trump also promised to “conduct the largest domestic deportation operation in American history.”

Trump in June proposed “automatically” issuing green cards to foreign nationals who graduate from U.S. colleges – comments that conflict with his efforts to curb both legal and illegal immigration during his time in office.

After the war between Israel and Hamas began last October, Trump promised to cancel the visas of “Hamas sympathizers.”

Harris

Her campaign released a video in July touting her support for increasing the number of Border Patrol agents, and she has often highlighted Trump's successful push to scuttle a bipartisan immigration deal that included some of the toughest border security measures in recent memory.

In June, the White House announced a crackdown on asylum applications to further reduce border crossings – a policy that Harris' campaign manager Julie Chavez Rodriguez told CBS News in July and that would continue under a Harris administration.

Harris has spoken only occasionally about her efforts as the border became a political vulnerability for Biden. But it put its own stamp on the government's efforts and enlisted the private sector. Harris launched the Partnership for Central America, which acts as a liaison between companies and the U.S. government.

Experts consider Harris' ability to secure private sector investment to be her most visible move in the region to date, but warn about the long-term sustainability of these investments.

Read more about Harris' And Trumps Viewpoints on key issues.