Cody John Cannon pleaded guilty to possessing methamphetamine with intent to distribute, in violation of 21 U.S.C. § 841(a)(1), (b)(1)(A). The district court 1 *74 sentenced him to the statutory minimum of 120 months in prison, and 5 years of supervised release. On appeal, his counsel has moved to withdraw and filed a brief under Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967). For the following reasons, we affirm.

The district court lacked authority to sentence Cannon below the 10-year statutory minimum. See United States v. Gregg, 451 F.3d 930, 937 (8th Cir. 2006); United States v. Chacon, 330 F.3d 1065, 1066 (8th Cir. 2003). Further, Cannon must pursue any ineffective-assistance claims in a proceeding under 28 U.S.C. § 2255. See United States v. Hughes, 330 F.3d 1068, 1069 (8th Cir. 2003). Finally, having reviewed the record under Penson v. Ohio, 488 U.S. 75, 80, 109 S.Ct. 346, 102 L.Ed.2d 300 (1988), we find no nonfrivolous issues. Accordingly, we affirm the district court’s judgment and we grant counsel’s motion to withdraw on condition that counsel inform appellant about the procedures for filing petitions for rehearing and for certiorari.