Repeated scandals involving Secret Service agents are "absolutely not" evidence of a cultural problem within the agency, its Director Julia Pierson said Tuesday.

"This is isolated incidents of misconduct and we're working to correct that behavior every day," Pierson told reporters after she met with the Senate Homeland Security Committee. Asked why, if they are isolated incidents, these scandals keep occurring, she added: "We're humans and people make mistakes."

Pierson spent more than an hour meeting with the committee, one week after three agents were sent home after allegedly getting drunk in Amsterdam the night before they were supposed to be protecting President Obama -- which prompted several lawmakers to decry the agency's culture and demand further oversight.