South Korea’s impeached president vowed to “fight until the end” as authorities attempt to arrest him over his controversial declaration of martial law in early December.

Yoon Suk Yeol addressed supporters gathered outside his official residence in a letter sent on Wednesday, vowing to persist in his fight to defend the nation.

The letter, which was shared by Seok Dong-hyeon, one of Mr Yoon’s lawyers, said he watched a live stream of protests on YouTube and was grateful for their efforts.

He expressed concern about everyone’s health in the cold weather.

Mr Yoon wrote: “Currently, the Republic of Korea is in danger due to the manoeuvres of sovereignty-infringing forces and anti-state elements from within and outside the country. Together with you, I will fight to the end to protect this country.”

The opposing Democratic Party quickly condemned the letter. Jo Seoung-lae, a party spokesman, said Mr Yoon was “trying to stage insurrection” and “inciting his supporters to an extreme clash”.