In these consolidated appeals, Francillon Debreus appeals the district court’s denial of his motion for a sentence reduction under 18 U.S.C. § 3582(c) (2012) and he seeks to appeal the district court’s order *163 denying relief on his 28 U.S.C.A. § 2255 (West Supp. 2018) motion. The order denying the § 2255 motion is not appealable unless a circuit justice or judge issues a certificate of appealability. 28 U.S.C. § 2253(c)(1)(B) (2006). A certificate of appealability will not issue absent “a substantial showing of the denial of a constitutional right.” 28 U.S.C. § 2253(c)(2) (2006). When the district court denies relief on the merits, a prisoner satisfies this standard by demonstrating that reasonable jurists would find that the district court’s assessment of the constitutional claims is debatable or wrong. Slack v. McDaniel, 529 U.S. 473, 484, 120 S.Ct. 1595, 146 L.Ed.2d 542 (2000); see Miller-El v. Cockrell, 537 U.S. 322, 336-38, 123 S.Ct. 1029, 154 L.Ed.2d 931 (2003). When the district court denies relief on procedural grounds, the prisoner must demonstrate both that the dispositive procedural ruling is debatable, and that the motion states a debatable claim of the denial of a constitutional right. Slack, 529 U.S. at 484-85, 120 S.Ct. 1595.

We have independently reviewed the record and conclude that Debreus has not made the requisite showing. Accordingly, we deny a certificate of appealability and dismiss Debreus’ appeal from the denial of his § 2255 motion.

We review the district court’s decision on whether to reduce a sentence for abuse of discretion. United States v. Munn, 595 F.3d 183, 186 (4th Cir. 2010). Because Debreus’ Guidelines sentence was not lowered due to amendments to the Guidelines, we conclude that the district court did not abuse its discretion in denying the motion and affirm.

Accordingly, we deny a certificate of appealability and dismiss the appeal from the denial of the § 2255 motion and affirm the appeal from the district court’s order denying the § 3582(c) motion. We also deny Debreus’ motion to vacate the district court’s order. We dispense with oral argument because the facts and legal contentions are adequately presented in the materials before this court' and argument would not aid the decisional process.

No. 12-7640 DISMISSED.

No. 13-7439 AFFIRMED.