US Secret Service director Kimberly Cheatle resigned on Tuesday after the agency came under harsh scrutiny for its failure to stop a would-be assassin from wounding former president Donald Trump during a campaign rally.
The Secret Service, which is responsible for the protection of current and former US presidents, faces a crisis after a gunman was able to fire on Mr Trump from a roof overlooking the outdoor rally in Butler, Pennsylvania, on July 13.
Ms Cheatle faced bipartisan condemnation when she appeared before the House of Representatives Oversight Committee on Monday, declining to answer questions from frustrated politicians about the security plan for the rally and how law enforcement responded to the suspicious behaviour of the gunman.
President Joe Biden, who has ended his re-election campaign, accepted her resignation.
"Jill and I are grateful to Director Kim Cheatle for her decades of public service," he said, referring to his wife.
"She has selflessly dedicated and risked her life to protect our nation throughout her career in the United States Secret Service. We especially thank her for answering the call to lead the Secret Service during our administration and we are grateful for her service to our family."
Her resignation was first reported by NBC and the Associated Press.
Several Republican and Democratic politicians called on her to resign.
Mr Trump, the Republican presidential candidate, was grazed in the right ear and one rallygoer was killed. The gunman, identified as 20-year-old Thomas Crooks, was shot and killed by a US Secret Service sniper.
Ms Cheatle, who has led the agency since 2022, told legislators she took responsibility for the shooting, calling it the largest failure by the Secret Service since Ronald Reagan, president at the time, was shot in 1981.
The Secret Service faces investigations from multiple congressional committees and the several watchdogs of the US Department of Homeland Security, its parent organisation, over its performance.
Mr Biden had earlier called for an independent review.
"As a leader, it takes honor, courage, and incredible integrity to take full responsibility for an organisation tasked with one of the most challenging jobs in public service," the President said.
"The independent review to get to the bottom of what happened on July 13 continues, and I look forward to assessing its conclusions. We all know what happened that day can never happen again."
Mr Biden announced that he will appoint a new director "soon".
Much of the criticism has focused on the failure to secure the roof of an industrial building where the gunman was perched about 140 metres from the stage where Mr Trump was speaking.
The rooftop was declared outside the Secret Service security perimeter for the event, a decision criticised by former agents and lawmakers.
Ms Cheatle held a top security role at PepsiCo when Mr Biden named her Secret Service director in 2022. She previously served 27 years in the agency.
She took over following a series of scandals involving the Secret Service that scarred the reputation of the elite and insular agency.
Ten Secret Service agents lost their jobs after revelations they brought women, some of them prostitutes, back to their hotel rooms ahead of a trip to Colombia by Barack Obama, president at the time, in 2012.
The agency also faced allegations that it erased text messages from around the time of the January 6, 2021, attack on the US Capitol. Those messages were later sought by a congressional panel probing the riot.
