Secret Service Director Julia Pierson has resigned, a day after bitingly critical questioning by Congress about a White House security breach and amid increasing calls for her departure.

Homeland Security Secretary Jeh Johnson said Wednesday that Pierson offered her resignation, and he accepted it.

"The president concluded that new leadership was required," White House Press Secretary Josh Earnest said Wednesday. He said Obama called Pierson on Wednesday to thank her for her service to the Secret Service and to the U.S.

Pierson will be replaced for the time being by Joseph Clancy, a former special agent in charge of the president's protective detail who retired in 2011. He will serve as acting director until permanent replacement for Pierson is found.

The administration is awaiting a review to determine whether more people will be leaving, Earnest added Wednesday.

Pierson had spent 30 years with the Secret Service. She took over the embattled agency last year after embarrassing incidents involving misconduct by officers and agents, including the 2012 Colombia prostitution scandal.

Her resignation came one day after she testified before the House Oversight and Government Reform Committee in a congressional hearing focused on recent security lapses at the White House.

High-ranking lawmakers from both parties Wednesday had been urging her to resign, as support for her eroded in the wake of her poorly received testimony about the White House break-in earlier this month.

"There has to be accountability when that is not the case," added House Minority Leader Nancy Pelosi, who also backed calls for an independent investigation.

The Sept 19. incident involving a Texas Army veteran who jumped the White House fence and was able to make it deep into the presidential mansion before being stopped is now just one of several embarrassing disclosures about lapses in presidential security involving the Secret Service.

The alleged intruder, Omar J. Gonzalez, pleaded not guilty through his attorney Wednesday in federal court.

Check back for more on this breaking news story.