Facing growing criticism over a massive security failure, the US Secret Service on Monday vowed to cooperate with an independent review after a shooter was allowed to open fire on Donald Trump.
The 78-year-old former president was injured but survived an assassination attempt at a campaign rally in Pennsylvania on Saturday, a brazen attack that shocked a nation already deeply polarized ahead of the November election.
"The Secret Service is working with all involved Federal, state and local agencies to understand what happened, how it happened, and how we can prevent an incident like this from ever taking place again," the agency's director Kimberly Cheatle said in a statement.
"We understand the importance of the independent review announced by President (Joe) Biden yesterday and will participate fully," Cheatle added.
Trump was speaking at a rally in Butler, Pennsylvania when multiple bangs rang out.
He clutched his ear, with blood visible on his ear and cheek, then ducked to the floor as Secret Service agents swarmed onto the podium, surrounding him and rushing him to a nearby vehicle.
The shooter and a bystander were killed, and two spectators injured.
Biden ordered a full review of security at the rally, as well as at this week's Republican National Convention in Milwaukee, Wisconsin, where Trump will be crowned the party's presidential nominee.
The Secret Service faces intense scrutiny over how a gunman aiming an assault rifle was allowed to take position on a roof some 500 feet (150 meters) from one of the most protected political figures on the planet.
And the questions grew louder when phone footage emerged of people sighting the gunman and trying to warn security before he opened fire.
With Trump set to star at the convention, Cheatle said the agency was working to toughen security at the event.
The Secret Service designs plans for major events "to respond to a kinetic security environment and the most up-to-date intelligence," her statement said.
Trump added to the concerns on Monday, calling for Secret Service protection for independent presidential Robert F. Kennedy "in light of what is going on in the world today."
"Given the history of the Kennedy Family, this is the obvious right thing to do!" Trump wrote on his Truth Social web site.
Kennedy, who has no chance of winning the election, comes from America's most famous political clan.
His uncle, President John F. Kennedy, was assassinated in Dallas, Texas in 1963. Five years later, the candidate's father, Robert, was shot to death in Los Angeles.
The US Secret Service is responsible for the safety of the president, vice president and former presidents, and their families, as well as major election candidates and visiting foreign heads of state.
