Washington (CNN) -- Secret Service Director Julia Pierson, called to Capitol Hill to explain misbehavior by her agents, insisted the problems were not reflective of the broader culture at her agency.
"These are isolated incidents of misconduct and we're working every day to correct our behavior," Pierson told reporters Tuesday after leaving a closed meeting with top senators on the Homeland Security and Governmental Affairs Committee.
But there have been numerous incidents of misconduct in recent years.
In the latest, three agents who were part of the President's advance security detail were sent home from the Netherlands after one of them was found passed out in a hotel hallway after a night of drinking. Also, a Secret Service officer in Florida was involved in a traffic accident and alcohol use was suspected.
"We're human and we make mistakes," Pierson said when asked why the agency continues to be plagued by such problems.
Chairman Tom Carper of Delaware said just a "handful" of Secret Service members are "shaming and smearing" the agency, which employs thousands of people. He said he discussed with Pierson modifying hiring and firing rules and making other policy changes if they would help her deal with the problem.
"All of us are human, all of us have temptation and some of these jobs, they travel a lot, they're away from home a lot. They have their own foibles," Carper said. "This director is very committed to making sure there's a set of discipline policy standards to follow."
Pierson, a Secret Service veteran, is the first woman to head the agency. She was appointed to the post by President Obama about a year ago in the wake of an incident involving drinking and prostitutes ahead of the President's 2012 visit to Cartagena, Colombia.
"I have made clear to the entire workforce that I will not tolerate unprofessional behavior or misconduct at any level -- both on and off duty," Pierson told the senators, according to prepared remarks released by the Secret Service. "I remain committed to swiftly and vigorously addressing any instances of misconduct that are brought to my attention."
Pierson told the senators she has instituted several changes beyond those including appointing a chief integrity officer, centralizing the discipline process at the agency, and implementing enhanced ethics and integrity training for employees.
Sen. Kelly Ayotte, R-New Hampshire, was one of a handful of senators to go to the hour-long meeting, which was also attended by Pierson's boss, Secretary of Homeland Security Jeh Johnson.
"We've got to get to the bottom of this because it's important to our government to have the Secret Service carry itself with the highest of standards that we expect of them, not only to make sure that ... the President of the United States but all of our leaders are protected," said Ayotte who likened recent incidents to a "fraternity party."
Sen. Tom Coburn of Oklahoma, the top Republican on the committee, told CNN the senators outlined in the meeting suggestions to the agency to deal with problem but he wouldn't say what those suggestions were. He said he has confidence in Pierson to stay on the job and deal with the issues.
"She's obviously embarrassed because it's a reflection on her management but I'm willing to give her the benefit of the doubt right now and see if things don't change," Coburn said.