Secret Service chief Julia Pierson testified Tuesday about her agency’s problems dealing with security threats. (J. Scott Applewhite/AP)

Homeland Security Secretary Jeh Johnson on Wednesday accepted the resignation of Secret Service chief Julia Pierson, one day after she went through a grilling on Capitol Hill over her agency’s recent problems with White House security.

Johnson said he appointed Joseph Clancy, a former special agent in charge of the Secret Service’s presidential detail, as the agency’s interim director.

He also directed Homeland Security Deputy Secretary Alejandro Mayorkas to lead a review of the Sept. 19 White House breach in which a military veteran armed with a knife jumped a fence and made his way all the way to the East Room before being apprehended.

Johnson also announced that an independent review panel “will be named shortly” to examine the breach. He said the group will provide an assessment and recommendations by Dec. 15.