Seoul, South Korea (CNN) -- South Korean President Park Geun-hye apologized Monday for a damaging scandal involving a spokesman she fired last week over allegations of sexual misconduct in the United States.
The former aide, Yoon Chang-jung, is accused of making inappropriate advances toward a female student who was hired as a guide while Yoon was in Washington for Park's first official visit to the United States last week.
"I am very sorry that an unsavory incident, which a public official should never be involved in, happened near the end of my visit to the U.S. and hugely disappointed the people," Park said Monday at a meeting with senior officials. It was the first time she has commented publicly on the matter.
Her office hasn't disclosed details of what Yoon, 56, is alleged to have done, and Washington police have said only that they are investigating a report of a sexual abuse misdemeanor without specifically mentioning Yoon by name.
But South Korean news media have widely reported that Yoon is accused of grabbing the buttocks of the young woman, who has not been identified, after drinking with her.
On Saturday, Yoon denied the allegations circulating about him, saying he had patted the woman on the waist once and encouraged her to "live life to the full in the States and be successful."
"I swear I did not have any intention of sexually harassing her, and I did not molest her," Yoon said during a news conference in a Seoul restaurant.
"Now, I deeply regret not properly understanding the American culture, and I offer my sincere word of consolation to the guide," he said.
Yoon also denied allegations in the South Korean press that he had called the woman to his room the morning after the incident and answered the door undressed.
He said he had only answered the door in his underwear because he believed it was somebody with an urgent message for him.
"I never imagined my guide would have come," he said.
He apologized to Park, South Korea's first female president, for the "trouble" he had caused.
State visit overshadowed
The scandal has cast a pall over Park's five-day visit to the United States, her first high-profile trip since her inauguration in February.
Before news emerged of Yoon's dismissal and the allegations against him, the visit had generally been considered a success, with Park and President Barack Obama reaffirming the U.S.-South Korean alliance in the face of recent threats from North Korea.
Yoon is alleged to have made the inappropriate advances toward the woman on Tuesday night, hours after Park held talks with Obama.
He said his boss, chief presidential press secretary Lee Nam-ki, told him to leave Washington quickly and return to South Korea as soon as the allegations of misconduct began to surface.
Yoon said he told Lee he had done nothing wrong and wanted to stay and explain the situation. But he said he followed his supervisor's order and gone to the airport.
Lee made a statement to the media on Thursday in Los Angeles (Friday morning in South Korea), saying Yoon had been dismissed after he had "damaged the dignity of the country."
By the time Park stepped off the plane that brought her back to South Korea on Friday evening, a media firestorm was raging over the scandal, and opposition parties were demanding a public apology.
After earlier apologies by senior members of her staff, Park addressed the matter herself on Monday.
She apologized for the "shock" that she said the student and her parents must have experienced.
South Korea "will take whatever measures are necessary and will actively cooperate with the U.S. investigation," Park said.
Yoon, a former journalist and political columnist, served as spokesman for Park's transition team before his appointment, according to the semiofficial South Korean news agency Yonhap.
Critics had said at the time he was unsuitable for the job as spokesman, claiming his columns were sensational and biased, Yonhap reported.
Journalist Soobin Park reported from Seoul, South Korea. CNN's Jethro Mullen reported and wrote from Hong Kong.