Lionel Messi has warned his Argentina teammates that nothing will be easy for them after they won their final Copa América warmup fixture against Guatemala on Friday.

Messi and Lautaro Martínez each scored twice in the 4-1 win at Fedex Field, Washington D.C., after a Lisandro Martínez own goal in the opening minutes had given the central Americans a surprise lead.

After the match, Messi admitted that defending the title that they won in 2021 was going to be a difficult challenge.

"It's going to get harder and harder for us, nothing is going to be easy for us," he said. "But we're going to try again.

"We are working with the same desire as always, with the same intensity in each training session and facing these games as we always do."

Argentina announced their official squad for the tournament on Saturday.

"I have decided which players will be left out, but first I am going to inform them," head coach Lionel Scaloni said.

"The decision always involves looking for the best for the team. This is the most difficult list of all because we have had complications."

Scaloni added that Messi knows he will play all the team's games "as long as he is healthy."

Copa América begins on June 20 as Argentina face Canada at Mercedes-Benz Stadium in Atlanta.

Information from ESPN's Lizzy Becherano contributed to this report.