Messi's warning as Argentina gear up to face debutants Canada in Copa opener
The Argentines, who won the tournament in 2021 and went on to lift the 2022 World Cup, are no strangers to Copa America success.
They reached the finals in 2015 and 2016 and finished third in 2019.
This year's tournament brings together 10 South American teams and six from North and Central America and the Caribbean, in the 48th edition of the tournament, hosted for the second time by the United States.
Holding the tournament's all-time record with 34 top-three finishes and 128 match victories, Argentina are a formidable Copa force.
Messi, tied for seventh place in the tournament's all-time scoring chart with 13 goals, also holds the record with 17 assists.
On Thursday he's expected to surpass Chile's Sergio Livingstone record by playing in his 35th Copa America match.
Argentina, coached by Lionel Scaloni and featuring 21 players from their World Cup-winning squad, are tipped to make it to the final on July 14 in Miami, Florida.
However, Messi insists they will not be complacent.
"Today, we can say that we are the best because we are the world champions. But that does not make us believe that we are going to win this Copa America by walking," Messi said.
Ranked number one in the FIFA world rankings, Argentina will face 49th-ranked Canada.
With newly appointed American coach Jesse Marsch, Canada are using the tournament as preparation for the 2026 World Cup which they will co-host with the U.S. and Mexico.
Canada's Copa America squad features only two players over age 30 - goalkeeper Maxime Crepeau (30) and midfielder Jonathan Osorio (32) - and 15 are aged 25 or younger.
"I think it's been good for this new group. It's kind of a new era and guys are responding really well," said the experinced Osorio.
The youthfulness contrasts with Messi, who turns 37 on Monday and has shown no signs of slowing down, with 12 goals in 12 matches for Inter Miami in the MLS this season.
Canada's next match is against Peru on Tuesday, the same day Argentina face Chile. Both teams will wrap up their group games on June 29 with Canada taking on Chile and Argentina playing Peru.