US Secret Service Director Kimberly Cheatle acknowledged to Congress on Monday that she and her agency fell short in preventing an attempted assassination that injured Republican presidential candidate Donald Trump during a campaign rally in Pennsylvania on July 13.

"We failed. As the director of the United States Secret Service, I take full responsibility for any security lapse," Cheatle stated before the House of Representatives Oversight Committee, amid calls from Republicans for her resignation.

Cheatle described the assassination attempt on former President Donald Trump as the most significant operational failure at the Secret Service in decades. She refuted claims that the agency lacked resources to protect Trump, noting that security measures had been enhanced prior to the incident.

"The level of security provided for the former president increased well before the campaign and has been steadily increasing as threats evolve," Cheatle emphasized. "Our mission is not political. It is literally a matter of life and death."

Monday's hearing was the first congressional oversight session on the attempted assassination. FBI Director Christopher Wray is scheduled to appear before the House Judiciary Committee on Wednesday, and House Speaker Mike Johnson plans to introduce a bipartisan task force to coordinate House investigations.

Despite calls for her resignation from prominent Republicans like Johnson and Senate Minority Leader Mitch McConnell, Cheatle has resisted. Republican House Oversight Committee member James Comer reiterated the demand for her resignation during the hearing.

"It is my firm belief, Director Cheatle, that you should resign," Comer stated. "The Secret Service has thousands of employees and a significant budget. But it has now become the face of incompetence."

Democratic Representative Gerry Connolly commented, "Unacceptable incidents like this one highlight the fact that we are an increasingly polarized nation experiencing heightened political tensions."

The shooting at an outdoor campaign rally in Butler, Pennsylvania, resulted in Trump being wounded in the ear, one rally attendee killed, and another injured. The suspected shooter, 20-year-old nursing home aide Thomas Crooks, was killed by law enforcement. His motive remains unclear.

Lawmakers have expressed anger, attributing the suspect's proximity to Trump to security lapses at Cheatle's agency, which is tasked with protecting presidents and former presidents. The House Judiciary Committee revealed last week that the Secret Service was inadequately resourced for Trump's rally due to staffing shortages caused by a rival campaign event in Pittsburgh and a NATO summit in Washington.

Cheatle informed lawmakers that the agency protects 36 individuals daily, including world leaders such as Israeli Prime Minister Benjamin Netanyahu, who is set to address a joint session of Congress this week.

President Joe Biden ended his struggling re-election campaign on Sunday, endorsing Vice President Kamala Harris as his successor. He pledged to serve until the end of his term on January 20, 2025.