BISMARCK, N.D. (AP) — North Dakota Supreme Court Chief Justice Gerald VandeWalle announced Thursday that he will not seek reappointment by his colleagues to head the high court when his term expires at the end of the year.

VandeWalle, 86, is the longest-serving chief justice in state history and the oldest in the nation. VandeWalle announced his decision in an email to justices and district court judges Thursday afternoon.

VandeWalle told The Associated Press that he intends to remain on the court for the “immediate future” but not as chief justice.

“My mind is still good but I’m not as energetic as I use to be,” VandeWalle told the AP. “The court needs someone with more physical energy.”

VandeWalle was appointed to the Supreme Court on Aug. 15, 1978, by former Gov. Arthur Link, a Democrat. VandeWalle was reelected to his fourth 10-year term on the state’s high court in 2014. His term will expire in 2024.