South Korean president asked to submit documents relating to Dec. 3 martial law

Yoon is set to face trial by the country's Constitutional Court after parliament suspended him on Dec. 14, with the first hearing scheduled for Dec. 27.

According to the court’s spokesman Lee Jin, a notice was electronically delivered to Yoon on Tuesday, Yonhap News reported.

The embattled 63-year-old leader has been asked to provide his defense strategy as well as a list of evidence against impeachment charges, which include treason and insurrection.

Yoon's lawyer has rejected treason charges as "absurd" and is expected to attend the court hearing in person.

Early on Wednesday, Yoon defied a summons from a joint investigation team made up of officials from the Corruption Investigation Office for High-Ranking Officials (CIO), police, and the Defense Ministry.

On Sunday, he refused to be questioned by the prosecutor's office, which was conducting a separate investigation into allegations of his abuse of power, among other charges.

However, the prosecutor's office has joined the joint team led by the CIO, and all four departments will conduct a joint investigation.

Yoon's refusal to appear for questioning was "deliberate," CIO chief Oh Dong-woon told lawmakers.

Now, the prosecutors have summoned the president for further questioning on Saturday.

Yoon declared martial law on Dec. 3, but hours later, 190 lawmakers met and passed a motion to lift it, forcing him to reverse his decision. The incident sparked calls for his resignation, including from members of his People Power Party.

Yoon is the first sitting president to face treason and insurrection charges as well as an overseas travel ban. He can face arrest as well.