President Yoon Suk Yeol bows in gesture of apologies over controversies involving the first lady before public statement and news conference at the presidential office in Seoul on Thursday. (Yonhap)

President Yoon Suk Yeol on Thursday apologized to the public for causing worry over escalating concerns regarding an election interference scandal involving Yoon and his wife Kim Keon Hee, but defended her, saying she did not meddle in state affairs.

"No president is giving an excuse. It's all my fault," Yoon said.

Yoon's first public apology since his inauguration in May 2022 came at a press conference held in an apparent bid for a breakthrough in his policy reform drive. He has been suffering from a constant decline in his approval rating, which hit a record sub-20-percent low near the midpoint of his five-year term.

At the press conference, lasting an unprecedented 140 minutes, questions centered on the first lady's alleged election interference, a secret network of her aides inside the presidential office, her involvement in stock manipulation and her acceptance of a luxury handbag. On these allegations, Yoon said Kim should have conducted herself with greater caution and that her causing concern to the public is an "unquestionable wrong."

But the president denied that Kim played a role in state affairs, stressing that she was giving him advice as a wife.

Yoon countered claims made by the opposition parties that the first lady had attempted to interfere in the ruling People Power Party's electoral candidate nominations ahead of the April general election, drawing comparisons to the corruption scandal involving impeached former president Park Geun-hye and her confidante.

"If anyone wants to describe a first lady helping the President with election campaigning and managing state affairs in a well-rounded manner as an attempt to meddle in state affairs, we might need to redefine the word in the dictionary," said Yoon.

President Yoon Suk Yeol speaks at a press conference held in his office on Thursday. (Yonhap)

Yoon's wife was also speculated to have exerted influence on state affairs through presidential secretaries who had personal ties with her. The opposition parties have called for a special counsel probe into suspicions that Kim accepted luxury gifts and was involved in stock manipulation, allegations which the national prosecution recently dismissed.

Yoon claimed that since his tenure as the country's prosecutor-general -- before he entered politics in June 2021 -- Kim "has often been vilified" as his political opponents made exaggerated claims about his wife to attack him.

In this regard, Yoon's office is set to launch an office of the first lady. Yoon on Thursday approved the nomination of the presidential secretary who would lead the office, he told reporters, without disclosing further details, adding that the new office was hiring. Chang Soon-chil, a presidential secretary for civil affairs, will reportedly assume the post, but the presidential office did not immediately confirm the report.

Asked his view on whether she should continue her public role, the president said she should limit her appearances if the people "hate" to see her.

"If people love to see (Kim's public appearances), she will do them, if people hate to see (her), she will refrain from (public appearances)." Yoon said. "(Kim) has already stopped making public appearances except at diplomatic events that benefit the nation, and this trend will continue."

During the press conference, Yoon recalled when his personal phone number was mistakenly exposed to the public. Occurring at a time when he was considered a presidential contender, the incident caused Yoon's phone to be inundated by text messages.

Kim advised Yoon to reply to those messages and not to change his number, and they have tried to continue doing so to this day, Yoon said. In retrospect, he and his wife's failure to abide by the presidential communication protocol had taken its toll.

"I thought it was risky, but it had some bright sides," Yoon said.

President Yoon Suk Yeol's news conference is being televised at Seoul Station in central Seoul on Thursday. (Yonhap)

Also, Yoon referred to his former political consultant, Myung Tae-kyun -- a central figure behind the spiraling political scandal involving the Yoon family -- as "one of hundreds of people" who congratulated him on winning the 2022 presidential election.

A voice recording of Yoon and Myung, which the main opposition Democratic Party of Korea revealed on Oct. 31, indicated that Yoon had told a senior member of the party to let then-former four-term lawmaker Kim Young-sun vie for a parliamentary seat in a conservative stronghold in a June 2022 by-election. Kim won the election and served two partial terms until May this year. Another news report in September implied that Yoon's wife Kim had discussed with Myung a plan to have Kim Young-sun run for a sixth term, a bid which ended in failure.

Yoon also denied allegations that he attempted to manipulate a presidential election forecast as a presidential candidate, that he asked a ruling party's senior member for their choice of a specific candidate for a by-election in 2022, and that he abused his power to have Changwon, South Gyeongsang Province selected as a national industrial complex upon Myung's request.

"There is a lot of false information," Yoon said. "But I apologized anyway because for (our) improper behavior and our failure to maintain the presidential communication protocol by saying unnecessary things (to random people)."

If his words prove untrue and Yoon is revealed to have exercised favoritism, he said, he would not deserve to be president.