Opposition parties have delayed a vote on nominee Kim Meong-su taking issue with his past politically liberal activities. Moon's nominee for the Constitutional Court chief was also voted down at the National Assembly on Sept. 11.

"The judicial appointment is not a matter that can be delayed in light of the parties' interests," Moon said in the message read by his spokesman Yoon Young-chan.

"In respect of the democratic separation of powers, it's important that such courtesy and dignity should be maintained in the confirmation procedure of chief justice," he said. "I request the National Assembly to prevent an unprecedented judicial leadership vacancy."

Moon released the statement one day before he embarks on a five-day trip to New York to attend the U.N. General Assembly.

Kim came under intense parliamentary scrutiny over his political orientation and job credentials during his confirmation hearing Tuesday. Conservative parties cast Kim as another "liberal-leaning" addition to the top court, raising doubts over his political neutrality, while the ruling Democratic Party (DP)

 pitched him as a figure well suited to spearhead judicial reform.

Moon said he feels heavy about the confirmation of the chief justice nominee, lamenting that he may have lacked sufficient communication with parliament. The president said he will meet with the leaders of political parties after the U.S. trip.

"I tried hard to have smooth communication with the National Assembly, but it looks like it wasn't enough, which makes to have heavy footsteps," he said. "After returning from the U.N. General Assembly, I will invite representatives of political parties to discuss current issues including national security and ask for their cooperation."

This was the first time that Moon issued a public message regarding the National Assembly's confirmation of high-ranking nominees.

On Friday the presidential chief of staff apologized after Moon's pick for the SMEs and startups minister gave up his nomination in the wake of criticism over his religious and historical views.

Moon's previous picks for the justice and labor ministers, and a court justice designate, renounced their nominations amid public disapproval. Top security and science officials also bowed out over disputes about their qualifications. (Yonhap)