South Korean President Park Geun-hye said Tuesday that she'll resign if parliament comes up with a plan to transfer power, her latest attempt to fend off impeachment efforts and massive street protests amid prosecution claims that a corrupt confidante wielded government power from the shadows.

Opponents immediately called Park's conditional resignation offer a stalling tactic, and analysts said her steadfast denial that she has done anything wrong could embolden her enemies. The country's largest opposition party, the Minjoo Party, said it would not let Park's "ploy to avoid impeachment" interfere with a planned vote on impeachment on Friday.

Park, who did not take questions from reporters after her live address to the nation, said she will "leave the matters about my fate, including the shortening of my presidential term, to be decided by the National Assembly," referring to parliament.

"If the ruling and opposition parties discuss and come up with a plan to reduce the confusion in state affairs and ensure a safe transfer of governments, I will step down from the presidential position under that schedule and by processes stated in law," she said.

How exactly this might play out is still unclear. But some saw Park's speech as a clear effort to avoid leaving office, despite the resignation language.

People watch a television broadcast of a news report on President Park Geun-hye releasing a statement to the public in Seoul early Tuesday. (Kim Hong-Ji/Reuters)

One clue that she was trying to buy time, said Yul Shin, a politics professor at Seoul's Myongji University, was her comment on "shortening" the presidential term, something he said would require a time-consuming constitutional amendment. Park is to end her single five-year term in early 2018.

"There is no possibility that the opposition parties will accept her offer; not when the public is this angry," Shin said. "She apparently wanted to buy more time, but in the end she might have hastened the end of her presidency."

Friend allegedly exploited ties

Park's speech came as opposition parties were closing in on an impeachment motion. Even some of her allies have called for her to "honourably" step down rather than face impeachment.

The country's two largest opposition parties were also planning on Tuesday to nominate a special prosecutor to independently investigate the scandal.

Park, in her speech, continued to deny accusations by prosecutors that she colluded in the criminal activities of her longtime friend, Choi Soon-sil, the daughter of a cult leader, who, despite having no official role in government, allegedly had a say in policy decisions and exploited her presidential ties to bully companies into giving large sums of money to businesses and foundations that Choi controlled.

Samsung Group and the country's largest pension fund are among the corporations who have been ensnared in the investigation.

"Not for one moment did I pursue my private gains, and I have so far lived without ever harbouring the smallest selfish motive," Park said. "The problems that have emerged are from projects that I thought were serving the public interest and benefiting the country. But since I failed to properly manage those around me, [everything that happened] is my large wrongdoing."

Protesters last month wear cut-outs of Park, right, and Choi Soon-sil, whose close friendship with the president looks likely to topple the government. (Kim Hong-Ji/Reuters)

Instead of buying her more time, Park's conditional resignation offer may embolden street protesters and further fan the anger of her critics because she continues to deny wrongdoing over the scandal, said Choi Chang Ryul, a politics professor at South Korea's Yongin University.

Her term had been scheduled to end in the first half of 2018.

Prosecutors have so far indicted Choi, two ex-presidential officials and a music video director known as a Choi associate for extortion, leakage of confidential documents and other charges.

Park, who has immunity from prosecution while in office, has refused to meet with prosecutors. Her lawyer, Yoo Yeong-ha, has described prosecutors' accusations against Park as groundless.

South Korea's first president, Syngman Rhee, quit and then fled to Hawaii amid a popular uprising in 1960. The succeeding government was overthrown by a coup by Park's late father, the military dictator Park Chung-hee, whose rule also abruptly ended after he was assassinated by his spy chief in 1979. Choi Kyu-hah then became acting president, but he was forced out of office eight months later after a military coup led by Chun Doo-hwan, who would eventually become president.