The striker was stretchered off and required an oxygen mask during West Brom's 2-1 win at Stoke on Saturday.
A club statement read: "Albion striker Daryl Dike will be sidelined for six to nine months after suffering an Achilles tendon injury at Stoke City on Saturday.
"A scan has since confirmed surgery is required to repair a full rupture of the USA international's right Achilles, after which he will begin his rehabilitation.
"Albion's medical and sports science teams will provide Dike with all the support he requires to return to full fitness later this year."
Dike had put himself back into contention with the USMNT after scoring seven goals in 23 Championship matches for West Brom this season.
Dike, 22, was not part of the USMNT roster to face Mexico on Wednesday because the match fell outside of a FIFA international window and the team almost entirely comprised U.S. domestic players.
"Words cannot be made to describe how I feel right now," Dike wrote on social media. "Beyond gutted for this injury as it feels like nothing I do can seem to go my way at the moment.
"In life things will happen that are beyond your control despite your best efforts, that you cannot go back and change, but need to accept and choose how to react... Now is my time to bounce back and give myself a positive reaction."
The Oklahoma native joined West Brom in January 2022 from Major League Soccer's Orlando City. He debuted as a second-half sub against Queens Park Rangers that Jan. 15 and sustained a season-ending hamstring injury in his first start, against Peterborough on Jan. 22.
Dike tore a thigh musle in this season's July 30 opener against Stoke and didn't return until he entered in the 90th minute against Stoke on Nov. 12, West Brom's last game before the World Cup break.
Information from the Associated Press was used in this report.