The win gave the USA a sweep of the group stage and a berth in the Division One quarterfinals against Costa Rica on Thursday
Valdez finished third in the 2018-2019 Development Academy U-15 age group with 21 goals in 22 games for the Galaxy.
Federico Oliva (Atletico Madrid) had the other goal for the USA against Suriname. Valdez, Oliva and Rafael Jauregui (Sac Republic FC) have combined for eight of the nine goals the USA has scored in three games.
Thursday's other quarterfinals: Mexico-Canada, Israel-Slovenia and Portugal-Haiti.
Aug. 7 in Bradenton, Florida
USA 4 Suriname 0. Goals: Valdez 3, pen. 13, 41; Oliva 30.
USA -- Brady; Tanton (Pukstas 36), Avila, Reynolds, Martinez (Leone 70+1), Jauregui, Valdez (Rotundo 48), Yohannes (Rodriguez 48), Hot; Oliva (Cisneros 48), Torres.
Suriname -- Khargoe (Fonkel 49); De Windt (Lima Po 48), G. De Mees, E. De Mees, Ligeon; Asongie, Jordan (Matabadal 49), Zijler, Pryor (Kamsi 62); Lodik (Adipie 49), Ost.