Gregory Holt, now Arkansas prisoner # 129616, appeals the district court’s denial of the petition for a writ of coram nobis that he filed with respect to his 2005 conviction of making threats against the President’s family. His motion to file a supplemental brief is GRANTED.

We review the district court’s “factual findings for clear error, questions of.law de novo, and the district court’s ultimate decision to deny the writ [of coram nobis] for abuse of discretion.” Santos-Sanchez v. United States, 548 F.3d 327, 330 (5th Cir. 2008), vacated on other grounds by 559 U.S. 1046, 130 S.Ct. 2340, 176 L.Ed.2d 559 (2010). This court’s “review is limited by the presumption of correctness of prior proceedings and the narrow range of claims cognizable in granting the” writ of coram nobis. United States v. Dyer, 136 F.3d 417, 422 (5th Cir. 1998).

Holt has failed to show that the district court abused its discretion by denying his petition. A writ of coram nobis is not a substitute for an appeal and will issue only if there is no other remedy available. See id. at 422. “[A] petitioner seeking coram nobis must exercise reasonable diligence in seeking prompt relief.” Id. at 427 (internal quotation marks and citations omitted). Thus, he must provide sound reasons for failing to seek appropriate relief earlier. Id. at 422. Holt’s failure to provide these reasons suffices to show that the district court did not abuse its discretion by denying his petition. See id.

AFFIRMED.