The political turmoil in South Korea has been taking a toll on the country's economy and diplomacy following the impeachments of the president and prime minister.

On Friday, South Korea's National Assembly passed a motion to impeach Prime Minister Han Duck-soo, with support from opposition parties. Han took over presidential duties after the impeachment of President Yoon Suk-yeol earlier this month.

The role of acting president will be assumed by Finance Minister and Deputy Prime Minister for Economic Affairs Choi Sang-mok.

Concerns over the deepening political crisis prompted a sell-off of the South Korean won on foreign exchange markets on Friday.

The currency weakened to the 1,480 won per dollar level at one point, the lowest in nearly 16 years, since March 2009.

The won has been on a decline since Yoon's short-lived declaration of martial law on December 3.

As acting president, Han has had telephone talks since December 14 with Japanese Prime Minister Ishiba Shigeru and US President Joe Biden.

South Korean media have raised concerns that the appointment of a second acting president within only two weeks could cause a stagnation on the country's diplomacy ahead of the swearing in of US President-elect Donald Trump on January 20.