Former President Trump said Vice President Harris’s planned visit to the US-Mexico border in Arizona on Friday is only for “political reasons,” as he has sought to keep immigration at the forefront of the campaign heading into November's election.

“After almost four years, Border Czar Kamala Harris has decided, for political reasons, that it’s time for her to go to our broken Southern Border,” Trump posted on Truth Social. “What a disgrace that she waited so long, allowing millions of people to enter our Country from prisons, mental institutions, and criminal cells all over the World, not just South America, many of those coming are terrorists, and at a level never seen before!”

Since Harris entered the race in July, Republicans have dubbed her Biden's “border czar,” a word some media outlets used after the president in 2021 asked her to “lead our efforts with Mexico and the Northern Triangle” and help with “stemming the migration to our southern border.”

Migrant encounters on the border hit a record high at the end of 2023, but border patrol apprehensions this past summer were down by almost half on the previous year, as the Biden administration imposed harder-line immigration measures.

Despite the drop, Harris has faced ongoing criticism from both parties on the issue. Six House Democrats backed a resolution in July that said Biden and Harris's "far left Democrat open border policies are to blame for this historic crisis."

Harris has sought to go on offense on the issue, arguing that she is committed to stopping illegal immigration while Trump opposed a bipartisan bill that would have helped curb illegal crossings.

The issue hits particularly close to home in Arizona, a key battleground state where Trump maintains a slight edge over Harris, according to DDHQ/The Hill's polling average.

The details of Harris’ Friday trip have not been publicized. It will be her second visit to the state since replacing Biden at the top of the Democratic ticket.

The Hill reached out to the Harris campaign for comment.