SEOUL, Jan 6, 2025 (BSS/AFP) - US Secretary of State Antony Blinken holds talks Monday in crisis-riven South Korea, seeking to encourage policy stability in the US ally, including in its complicated relationship with Japan.

Blinken, starting what will likely be his last trip as the top US diplomat, will be meeting his counterpart on the day an arrest warrant for impeached President Yoon Suk Yeol expires.

Before that meeting, Blinken held talks with acting president Choi Sang-mok. Choi has been in office just over a week and also serves as acting prime minister and finance minister.

Raucous protests were audible even before dawn from Blinken's hilltop hotel as crowds rallied in the snowy capital either in support or against the conservative president.

Yoon, until recently a darling of President Joe Biden's administration for his pro-US policies on the international stage, stunned South Korea by briefly imposing martial law on December 3.

Yoon quickly backed down when faced with street protests and quick action by the opposition-dominated parliament but the crisis was far from over, with lawmakers also impeaching his acting successor.

Investigators seeking to arrest Yoon failed on Friday after a six-hour standoff with his security service.

Blinken is not scheduled to meet Yoon and will hold a joint news conference with Foreign Minister Cho Tae-yul, who is not under threat of impeachment.

Blinken is expected to steer clear of taking partisan sides in the deeply divided country but instead will focus on policy continuity.

Yoon delighted the United States by seeking to turn the page on decades of friction with Japan, a fellow US ally that is also home to thousands of US troops.

Yoon joined Biden and Japan's then prime minister Fumio Kishida in 2023 for a landmark three-way summit that included a promise to step up intelligence cooperation on the key challenge of North Korea.

South Korea's progressive opposition, which has made Yoon's life miserable from parliament and is increasingly ascendant since the president's power grab, historically has taken a harder line on Japan over the legacy of its brutal 1910-1945 colonial rule of the Korean peninsula.

Opposition leader Lee Jae-myung -- who himself faces election disqualification in a court case -- also favours more diplomatic outreach with North Korea than the hawkish Yoon.

Before the crisis, South Korea had been looking at providing weapons to Ukraine, breaking an earlier taboo in response to North Korea sending troops to fight alongside Russia in its invasion.

- Awaiting Trump -

The turmoil and lack of a clear leader in Asia's fourth-largest economy comes just as the United States is in the midst of its own political transition.

While Biden has focused on nurturing US alliances, President-elect Donald Trump, who takes over on January 20, has been dismissive of what he sees as unfair commitments by the United States.

Trump said during his latest presidential run that if he were in power he would have strong-armed South Korea into paying $10 billion a year for the US troop presence, nearly 10 times what it contributes now.

But paradoxically, Trump forged a bond with the last progressive South Korean president, Moon Jae-in, who encouraged his attempts at deal-making with North Korea.

Trump, who once threatened "fire and fury" against North Korea, went on to meet three times with leader Kim Jong Un and said they "fell in love".

Trump's unusually personal diplomacy managed to lower tensions on the Korean peninsula but brought no lasting deal to end Pyongyang's nuclear programme.

Blinken will head to Japan later on Monday and then to France as he bids farewell by focusing on US alliances.