Argentina's new all-time leading goal-scorer Lionel Messi was lavished in praise by coach Gerardo Martino after the "best player in the world" guided last year's Copa America runners-up to yet another final.

Messi, who overcame a back problem at the start of the tournament, surpassed Gabriel Batistuta as Argentina's top scorer with his 55th international goal in Tuesday's comprehensive 4-0 win over the United States in the semifinals.

The captain's fifth goal of the centenary tournament helped Argentina to back-to-back Copa America finals following last year's penalty shootout loss to Chile.

Asked about Messi's historic night in Houston, Martino told reporters: "It makes me very happy what he has done. Very pleased that has been in this Copa America.

"It is great that the best player in the world is the leading scorer of the Argentina national team.

"But knowing how he is, he is happier about the team."

Argentina - seeking to end its 23-year wait for a major title having lost the 2014 World Cup final before going down to Chile last year - outclassed the USA at NRG Stadium.

Messi set up Ezequiel Lavezzi for the opening goal in the third minute before making history with a sublime free kick just past the half-hour mark.

Gonzalo Higuain scored a second-half brace to silence the Americans, with Argentina now awaiting either Chile or Colombia in Sunday's showpiece.

"What brings us closer to win the final is approaching the performance of today's match," Martino added.

"The answer we have to give on Sunday, only the result will determine whether we are the best or not."