SEOUL – Impeached South Korean President Yoon Suk Yeol issued a defiant statement to his conservative supporters gathered outside his residence in the capital of Seoul, vowing to “fight to the end” against what he called “anti-state forces,” as law enforcement prepared to detain him over last month’s martial law decree.

The Corruption Investigation Office for High-Ranking Officials has a week to execute its detainment warrant against Yoon, issued by a Seoul court on Tuesday. The warrant came after Yoon defied several requests to appear for questioning and blocked searches of his office, hindering an investigation into whether his short-lived power grab on Dec. 3 amounted to rebellion.

Oh Dong-woon, the anti-corruption agency’s chief prosecutor, has indicated that police forces might be deployed if Yoon’s security service resists the detention attempt, which could occur as early as Thursday. But it remains unclear whether Yoon can be compelled to submit to questioning.

In a message to hundreds of supporters gathered outside his residence Wednesday evening, Yoon said he would continue to fight against anti-state forces “violating our sovereignty” and putting the nation in “danger.” He applauded his supporters for their efforts to protect the country’s “liberal democracy and constitutional order” and said he was watching their protests on live YouTube broadcasts, according to a photo of the message shared by Yoon’s lawyers.

The liberal opposition Democratic Party, which drove the legislative vote that impeached Yoon on Dec. 14 over the martial law imposition, accused the president of trying to mobilize his supporters to block his detention and called for law enforcement authorities to execute the warrant immediately.

A growing number of Yoon’s supporters were again gathering near his residence on Thursday morning amid a heavy police presence, waving small South Korean and American flags and holding signs opposing his impeachment.

Yoon’s lawyers have argued that the court’s detainment warrant is “invalid,” claiming that the anti-corruption agency lacks legal authority to investigate rebellion charges. They also accuse the court of bypassing a law that says locations potentially linked to military secrets cannot be seized or searched without the consent of the person in charge.

Some experts believe the anti-corruption agency, which is leading a joint investigation with police and military authorities, would not risk clashing with Yoon’s security service, which has said it will provide security to Yoon in accordance with the law. The office may instead issue another summons for Yoon to appear for questioning if they are not able to execute the detainment warrant by Jan. 6.

Yoon’s presidential powers were suspended following the National Assembly vote to impeach him on Dec. 14 over his imposition of martial law, which lasted only hours but has triggered weeks of political turmoil, halted high-level diplomacy and rattled financial markets. Yoon’s fate now lies with the Constitutional Court, which has begun deliberations on whether to uphold the impeachment and formally remove Yoon from office or reinstate him.

To formally end Yoon’s presidency, at least six justices on the nine-member Constitutional Court must vote in favor.

The National Assembly voted last week to also impeach Prime Minister Han Duck-soo, who had assumed the role of acting president after Yoon’s powers were suspended, over his reluctance to fill three Constitutional Court vacancies ahead of the court’s review of Yoon’s case.

In the face of growing pressure, the country’s new interim leader, Deputy Prime Minister Choi Sang-mok, appointed two new justices on Tuesday, which possibly increased the chances of the court upholding Yoon’s impeachment.