Pulisic had two goals in the second half and Weston McKennie scored for a second straight game, leading the U.S. over Jamaica 3-1 in Wednesday night's semifinal.
The Nissan Stadium crowd of 28,473 was chanting "We Want Mexico!" in the closing minutes.
"It's definitely going to be a fun game," McKennie said. "I think the fans want it. You heard them saying, 'We Want Mexico!' I think we want it. I think we're ready for it, looking forward to it."
The Americans face El Tri at Chicago on Sunday night in the finale of a tripleheader of finals. The U.S. women play the Netherlands in the World Cup final at Lyon, France, and Brazil faces Peru for the Copa America title at Rio de Janeiro.
The U.S. is 6-4 in Gold Cup finals, including 1-4 against Mexico with a win in 2007 and losses in 1993, '98, '09 and '11. The defending champion Americans have won a team record 10 straight Gold Cup matches.
"We've already started preparing, already started watching them the last couple of days," U.S. coach Gregg Berhalter said. "It's a good team, quality players, good team concept, a lot of intensity that they play with. They can hurt teams. Having said that, they're also vulnerable, and we'll plan to be able to hurt them as well."
McKennie put the U.S. ahead in the ninth minute with his third international goal. The game was halted in the 16th minute for 1 hour, 28 minutes because of a lightning storm.
"I haven't really dealt with something like that since like youth soccer," Pulisic said. "It was strange. We tried to keep ourselves going, and in the end, everything worked out."
Pulisic made it 2-0 in the 52nd minute and Shamar Nicholson cut the deficit in the 69th. Pulisic got his second goal in the 87th, giving the 20-year-old 13 goals in 30 international appearances. Nine of Pulisic's 12 international goals have come in competitive matches.
Nicholson's goal was the first against the U.S. in the tournament and ended a 482-minute scoreless streak by the American defense.
"I'm really disappointed that we conceded a goal in this tournament, but it's a learning moment and something that looking back on it now, I'm glad we did because the guys had to dig deep," Berhalter said.
Jamaica was trying to reach its third straight Gold Cup final following losses to Mexico in 2015 and the U.S in 2017. The Reggae Boyz could not contain Pulisic and McKennie, a pair of 20-year-old midfielders.
"I think we lost the game in the center of the park tonight," Jamaica coach Theodore Whitmore said.
McKennie's goal developed from a long pass from Michael Bradley to Reggie Cannon on the side of the penalty area. Cannon crossed and Altidore had his back to the goal as he tapped the ball to a charging McKennie. McKennie's shot from about 6 yards sailed over the right hand of goalkeeper Andre Blake.
Altidore and Cannon had earned starts along with attacker Jordan Morris, and central defender Matt Miazga's as part of Berhalter's lineup shuffle.
Pulisic's first goal came after McKennie made a long pass to Morris, who ran free on a flank. Blake saved Morris' shot, but Pulisic was coming up from the left side and knocked in the rebound.
Nicholson scored on a header from Leon Bailey's cross. Blake made a diving save of Arriola's shot from the left side, but Pulisic was again ready for the rebound and sent a shot into the left side of the goal.
Mexico reached the final despite a roster missing Javier Hernandez, Carlos Vela, Hirving Lozano and Miguel Layun.
"We know Mexico's a great team," Pulisic said. "I think it's going to be a great game. I'm so excited for it."
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