HEREFORD, Arizona >> Donald Trump’s running mate JD Vance blamed Vice President Kamala Harris for illegal immigration during a visit to the U.S.-Mexico border in Arizona on Thursday and claimed that migrants were overwhelming U.S. schools and hospitals.

Vance, speaking in front of the border wall in the town of Hereford, called Harris a failed “border czar” and said she should have worked with U.S. agencies to deal with illegal crossings, even though Harris was tasked with a narrower role of addressing migration from Northern Central America.

“Kamala Harris as border czar was asked to coordinate all these functions in government and she’s done nothing,” he said.

Republicans have tried to hold Harris responsible for high levels of illegal immigration under President Joe Biden, a Democrat who dropped his presidential bid last month. Biden’s exit paved the way for Harris to become the likely nominee.

Harris has responded by emphasizing her support for a bipartisan U.S. Senate border security bill introduced earlier this year. Republicans rejected the bill after Trump came out in opposition.

“Donald Trump does not care about border security,” Harris said during a speech in Atlanta on Tuesday. “He only cares about himself.”

While the number of migrants caught illegally crossing the border soared to record levels under Biden, they have plummeted since Biden issued new border restrictions in June. U.S. Border Patrol caught around 57,000 migrants crossing illegally in July, two U.S. officials told Reuters, the lowest monthly total since September 2020 when Trump was still president.

Vance, a Republican U.S. senator from Ohio who often speaks of his childhood exposure to drug addiction, said Harris’ policies had allowed fentanyl to enter the U.S. although most convicted fentanyl traffickers in recent years were U.S. citizens.

Vance said American children “feel overwhelmed with migrant children who shouldn’t be there” and that hospital wait times “have exploded” because migrants are seeking healthcare.

The Trump campaign did not immediately provide supporting evidence for either assertion.

“The human toll of this is the thing that we cannot forget,” Vance said.