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.

"There are a handful of members of the Secret Service who are shaming and smearing this 150-year-old agency," said Sen. Thomas R. Carper (D-Del.), who chairs the Homeland Security Committee. He added that he is confident in the job that Pierson is doing as agency director.

Senators who emerged from the meeting insisted it was just the latest step in what will be a long-term process of sorting out whether further oversight -- or potentially change in leadership -- is needed atop the agency charged with protecting the president and other U.S. officials. For now, the senators said, they are confident that Pierson is committed to addressing the agency's problems.

"It was a very good meeting," said Sen Ronald H. Johnson (R-Wis), as he emerged from the meeting. "We share the same goals... Director Pierson takes her responsibility very seriously and we're going to work cooperatively together with her."

Senator Kelly Ayotte (R-N.H.) said after the meeting that she believes the Homeland Security Committee must exercise more oversight over the agency and that she was not willing to say that she had been fully reassured by the answers she received Tuesday from Pierson.

"We've got to get to the bottom of this," Ayotte said. "What we need obviously is a Secret Service that conducts itself with the highest standards and not what we've seen in some of these situations where it seems... more like a fraternity party."

The Netherlands drinking scandal -- in which one agent got so drunk the night before an assignment that hotel staff found him passed out in a hallway the next morning -- comes as the agency continues to mend a reputation marred  after a highly publicized sex scandal two years ago.

Some lawmakers have cited the  incident in the Netherlands as further evidence that the Secret Service has failed to eliminate a frat-boy culture marked by lax discipline and little accountability.