The leader of South Korea's ruling party, Han Dong-hoon, a day after a general election defeat, announcing to resign.

The ruling People Power Party was trounced by the opposition in parliamentary elections, leaving President Yoon Suk Yeol a lame duck for the remainder of his term.

Similarly, South Korean President Yoon Suk Yeol, promised "reform", as the head of his ruling party’s resignation increased the opposition's stranglehold on parliament.

Local media said People Power Party (PPP) leader Han Dong-hoon, Prime Minister Han Duck-soo and a string of senior aides also offered to step down.

Experts said the resignations turned Yoon into a lame duck president for the remaining three years in office, just as the country is facing challenges including a weak economy and an increasingly aggressive North Korea.

Yoon has taken a tough line with the nuclear-armed North while improving ties with Washington and former colonial occupier Japan.

South Korea uses a mix of first-past-the-post seats and proportional representation and has one legislative chamber. Presidents can serve only one five-year term.