Guatemalan citizen Jose' Domingo Her-nand Santos petitions for review of an order of the Board of Immigration Appeals (BIA) dismissing his appeal from the decision of an immigration judge (IJ) who denied him asylum, withholding of removal, relief under the Convention Against Torture (CAT), cancellation of removal, and special-rule cancellation under the Nicaraguan Adjustment and Central American Relief Act of 1997 (NACARA). Santos argues that (1) he qualified for at least one of the foregoing forms of relief, (2) the BIA erred by failing to detail its own rationale for denying relief after adopting the IJ’s reasoning, (3) he is entitled to cancellation of removal because his removal will present an exceptional and extremely unusual hardship to his United States citizen daughter, and (4) he is entitled to NACARA relief.

To begin, we conclude that the BIA sufficiently and adequately explained its decision. As to the denial of relief, Santos has not raised a viable legal or constitu *451 tional challenge to the discretionary denial of cancellation based on hardship to a qualifying relative. Further, his challenge to the denial of NACARA relief is based on the unreviewable factual determination that Santos failed to register in a timely manner for NACARA benefits. Finally, Santos waived his appeal of the agency’s asylum, withholding, and CAT determinations by failing to meaningfully challenge them in his brief. See Chay-Velasquez v. Ashcroft, 367 F.3d 751, 756 (8th Cir. 2004). 2

The petition for review is denied.