During a visit to the southern border shared with California and Mexico on Thursday, Speaker Mike Johnson ramped up attacks on the Vice President Kamala Harris, calling her a "San Francisco radical" who "bears responsibility for this disaster" as "border czar."

The visit included a press conference along a border fence called "Whiskey 8" in San Ysidro, California -- south of San Diego -- with California Republican Rep. Darrell Issa as well as a tour of the U.S. Customs and Border Protection facilities at the San Ysidro Port of Entry and Imperial Beach locations, Johnson's office told ABC News.

"We've had a very interesting tour here at the San Diego sector. This has become in many ways the epicenter of the Biden-Harris border catastrophe. And now we're very concerned in Congress that this illegal immigrant invasion is threatening even the integrity of our elections," Johnson said at a press conference held along a border fence.

Johnson claimed the situation in San Diego has worsened.

In recent weeks, San Diego has had the highest number of encounters of any border region in the U.S., according to a senior CBP official. But those numbers have declined by 60 percent since the new asylum restrictions from the Biden administration were put in place earlier this summer.

"[Biden's] executive order was too weak, too little too late, and it's not solving the problem," Johnson said Thursday.

Johnson said human trafficking and illegal narcotics are concerns at the border, specifically in San Diego.

Johnson's visit came hours after the House approved a resolution to condemn Harris' border policies. Six Democrats in vulnerable House races -- Reps. Mary Peltola, Don Davis, Henry Cuellar, Yadira Caraveo, Gluesenkamp Perez and Jared Golden -- voted with Republicans to pass the measure.

Ahead of the vote, House Minority Leader Hakeem Jeffries called the resolution "fake and fraudulent" during his weekly press conference.

"[Kamala Harris] was never assigned border czar. [Republicans] are making that up," Jeffries said.

Johnson last visited the border in January 2024 when the speaker led a delegation of 64 Republicans to tour the Eagle Pass, Texas, port of entry.

The House has passed its own border bill called the Secure the Border Act, but rejected the bipartisan Senate border bill after Trump pressured Republicans to kill the deal.

ABC News' Quinn Owen contributed to this report.