The disgraced leader will now remain in custody, with a new warrant allowing investigators to keep him for up to 20 days.

TOKYO (Kyodo) -- Japan is monitoring developments in South Korea with "particular and grave" concerns, the top government spokesman said Wednesday, following the detention of President Yoon Suk Yeol over his declaration of martial law in December.

As political changes loom, South Korea’s leadership crisis could affect ties with China, Japan and the US, observers say.

Who is Yoon Suk Yeol? Suspended South Korean president facing impeachment trial for martial law decree - Yoon threw his country into political turmoil by briefly declaring martial law last month

A Seoul court issued a warrant Saturday to detain impeached President Yoon Suk Yeol for an extended period over his botched martial law bid last month in the first such detention of a sitting South Korean president.

Foreign ministers Cho Tae-yul and Takeshi Iwaya held talks in Seoul, with South Korea still in the midst of President Yoon Suk Yeol's impeachment. They laid emphasis on security ties, and trilateral work with the US.

Donald Trump will be sworn in by Supreme Court Chief Justice John Roberts as the 47th U.S. president at a ceremony at the Capitol Building. The 78-year-old Trump then delivers his inaugural address. On day one, Trump has pledged to sign a host of executive orders on a raft of matters ranging from border security to oil and gas production.

Japan’s Foreign Minister Takeshi Iwaya will fly to Seoul for talks with his counterpart on Monday amid an ongoing political crisis in South Korea over short-lived martial law. Iwaya will be hosted by South Korean Foreign Minister Cho Tae-yul in what would be their first one-on-one meeting.

Thousands of South Koreans have gathered for rival demonstrations in the capital Seoul, either demanding the arrest of President Yoon Suk Yeol over his failed December 3 martial law decree or calling for his impeachment to be declared invalid.

More than 70 were killed and dozens more were injured in a fuel tanker fire and explosion along a highway in central Nigeria, authorities said Saturday.

South Korean investigators probing President Yoon Suk Yeol for alleged insurrection asked a Seoul court on Friday to extend his detention as the embattled leader again refused to be questioned.