President Park Geun-hye apologized Monday over allegations of sexual misconduct by her now-fired spokesman, as she struggled to bring growing public outrage over the unprecedented, embarrassing incident under control.

It was the first time Park has spoken about the case that has been rocking South Korea since revelations Friday that former spokesman Yoon Chang-jung allegedly made unwanted sexual advances toward his temporarily hired secretary while accompanying Park on her first trip to Washington.

"I am apologetic that an unsavory incident, which a public servant should never be involved in, occurred near the end of my visit to the U.S. and greatly disappointed the people," Park said during a weekly meeting with senior secretaries.

"I sincerely apologize about the shock the female student and her parents must have received and the scars left on the hearts of compatriots" in the U.S. by the case, she said.

Park promised to make every truth revealed "without a single speck of suspicion."

"We will take whatever measures are necessary and will cooperate actively in the U.S. investigation," she said. "Those involved must render active cooperation for the investigation without any exception and take due responsibility."

Park said she will use the incident as a chance to set discipline among the presidential staff. Should a similar incident happen again, senior secretaries involved must all take responsibility, she said.

But Park did not say whether she will accept the resignation of Yoon's boss, senior press secretary Lee Nam-ki.

"I hope this will serve as an opportunity for not only Cheong Wa Dae (staff), but also all public officials to reflect on their attitudes and have greater control over their own attitudes," she said.

Yoon, 56, allegedly grabbed the buttocks of the victim in her early 20s after drinking with her in Washington on Tuesday night, hours after Park held summit talks with U.S. President Barack Obama. He was also accused of presenting himself naked to her when she came to his hotel room.

Yoon, who was fired and returned home in the middle of the presidential trip, has flatly denied the allegations, claiming he only patted her on the waist in a gesture to encourage her to do a better job and that he was wearing his underpants when she came to his hotel room.

But presidential officials said that Yoon had admitted during an interview with Cheong Wa Dae ethics officers upon his return from the U.S. that he did touch her buttocks and that he was wearing nothing when she dropped in on him in his hotel room.

The case completely overshadowed Park's otherwise successful visit to the U.S., where she and Obama agreed to further upgrade the traditional alliance between the two countries while reaffirming that they are firmly united against threats from North Korea.

It also rekindled criticism that Park picked the wrong person from the beginning.

Yoon, a former journalist and political columnist, served as spokesman for Park's transition team before his appointment.

Critics said he was unfit for the job because his columns were sensational, biased and extremely right-leaning.

The case has also shown signs of a blame game between Yoon and his boss, senior press secretary Lee Nam-ki, over Yoon's claims that Lee forced him to return home in the middle of the trip, though he wanted to remain there to set things straight.

The sensational incident has been grabbing front-page headlines every day, with news media outlets churning out a string of stories on the unprecedented case, with many calling it "national humiliation" and criticizing the top office for mishandling the incident.

Cheong Wa Dae has been struggling to bring the case under control.

It has apologized for the third time in just four days, including Park's apology on Monday.

The senior press secretary offered the first apology on Friday, and presidential chief of staff Huh Tae-yeol apologized again Sunday, calling the case "unconditionally wrong," "very shameful" and "unacceptable by common sense."

Lee also offered to resign, and Huh said he and other presidential staff are also ready to take responsibility.

North Korea has also denounced the case, saying it shows that Park's U.S. visit ended in failure. (Yonhap News)