SEOUL - Senior aides to South Korea's impeached President Yoon Suk-yeol offered to resign en masse on Wednesday, a day after his office expressed regret over acting President Choi Sang-mok's approved of two new judges to a court set to decide Yoon's fate.

Yoon's chief of staff, policy chief, national security advisor and special advisor on foreign affairs and security, as well as all other senior secretaries, tendered their resignation, his office said in a statement, without elaborating.

The aides had repeatedly expressed their intent to step down in the wake of Yoon's botched attempt to declare martial law on Dec 3, but their resignations have not been accepted, said a presidential official, who declined to be identified owing to political sensitivities.

ALSO READ: South Korea court issues arrest warrant for President Yoon

The official said the senior secretaries have been assisting Choi since he took over as acting president. Two other officials said the aides do not participate in day-to-day government operations, but are required to report to Choi and attend meetings when necessary.

The aides' latest offer came a day after Choi's surprise approval to fill two vacancies on the Constitutional Court handling the impeachment trial against Yoon.

It brought the total number of justices to eight on the nine-member court. Any decision in the Yoon case will require the agreement of at least six judges.

Yoon's ruling People Power Party criticized Choi's decision as "dogmatic" and lacking sufficient consultations.

READ MORE: S. Korea's parliament ousts acting president, as Yoon goes on trial

Finance Minister Choi assumed the role of acting president on Friday after the impeachment of Prime Minister Han Duck-soo, who had been acting president since Dec 14 when Yoon was suspended from power.

Yoon faces investigations on allegations that he led an insurrection, and a Seoul district court on Tuesday granted approval for his arrest, the first for a sitting president.