Battling record-low approval ratings after just three months on the job, South Korea's conservative President Yoon Suk-yeol said Wednesday he was not fixated on his dire polling numbers.

Since taking office in May, Yoon has seen his approval ratings plunge to a low of 24 percent, and he said at a press briefing to mark 100 days in office that he would reflect on what had gone wrong.

But it is "more important to humbly examine the public sentiment reflected by the opinion polls rather than fixate on the number itself," he told reporters.

Yoon, a lifelong prosecutor with no prior experience in elected office, has made what analysts describe as a string of unforced errors during his first months in the role -- which is typically a honeymoon period for new presidents in South Korea.

His predecessor Moon Jae-in enjoyed approval ratings of about 70 percent at the same stage in his term, polling data showed, and Yoon started work with 52 percent of people polled thinking he was doing a good job.

Despite a steady drumbeat of criticism in local media over his team, Yoon said Wednesday he was not planning a wholesale reshuffle to try and appease angry voters, who have deserted him in droves, polls show.

"Personnel reshuffle should be carried out carefully rather than for political purposes to turn around... approval (ratings)," he said, adding that he wanted people to give his administration more time.

In the latest misstep, his office released a photo showing Yoon at a basement apartment in Seoul where three people died in flooding last week, captioned: "People's safety is utmost priority".

The image was widely lambasted as an insensitive PR stunt politicising the tragedy. His office later took it down from his social media pages.

He has also been criticised for mishandling US House Speaker Nancy Pelosi's high-profile visit to South Korea after a contentious stop in Taiwan.

His ministerial appointments have been dogged with dropouts and resignations, and his decision to relocate from the presidential Blue House has made him a topic of derision online.

"The polls collectively show that the public see Yoon as not being presidential," political commentator Shin Jang-sik told AFP.

"His words are far short of what was needed... People will likely see his speech today as indicative of his lack of willingness to change course."

Yoon took office vowing to get tough on North Korea, but said Wednesday he did not support regime change by force and remained willing to offer massive aid to Pyongyang -- if Kim Jong Un will give up his nuclear weapons.

Analysts say the chances of Pyongyang accepting such an offer -- first floated during Yoon's inaugural speech -- are vanishingly slim, as North Korea, which invests a vast chunk of its GDP into weapons programmes, has long made it clear it will not barter its missiles away.

When asked if he would consider acquiring nuclear weapons if Kim does not halt his nuclear programme, Yoon said he would "uphold the principle of Non-Proliferation of Nuclear Weapons to the end".

North Korea has conducted a record-breaking blitz of weapons tests this year, and is widely believed to be preparing for another nuclear test.