U.S. Secret Service Director Kimberly Cheatle acknowledged before Congress her agency failed to protect Republican presidential candidate Donald Trump during a July 13 rally in Pennsylvania. Cheatle took full responsibility for the security lapse.

Cheatle described the attempt on Trump’s life as the most significant operational failure at the Secret Service in decades.

Cheatle has so far resisted calls for her resignation from Republican leaders, including Johnson and Mitch McConnell.