U.S. Secret Service Director Kimberly Cheatle, who came under scrutiny for the agency's failure to prevent the assassination attempt on former President Donald Trump, has resigned, according to two sources familiar with the decision.

Cheatle had faced calls to step down since the shooting at a Trump rally on July 13, which left one attendee dead and two others critically injured.

In an interview with ABC News after the attack, Cheatle called the incident "unacceptable" and said it was her responsibility to ensure nothing like it will happen again.

"The buck stops with me," she said. "I am the director of the Secret Service, and I need to make sure that we are performing a review and that we are giving resources to our personnel as necessary."