Argentina captain Messi, one of the biggest stars in Russia, said his international future will be determined by his country's performance at the World Cup.
"It will depend on how far we go, how we're going to finish" at the finals, Messi said in an interview with Spanish daily Sport.
"We've just lost three finals in a row, which has led to us going through some difficult moments with the press," the Barcelona forward added.
Argentina lost the 2014 World Cup final 1-0 to Germany after extra time, before suffering successive defeats by Chile on penalties at the Copa America in 2015 and 2016.
Messi, who will turn 31 during the World Cup, believes Spain, Brazil, Germany, France and Belgium are the leading contenders for the title.
Meanwhile, Portugal midfielder Manuel Fernandes said Cristiano Ronaldo "doesn't look at all worried about his future" as the Real Madrid superstar contemplates a possible exit from the Spanish giants this summer.
There has been intense speculation over Ronaldo's future after he suggested he could have played his last game for Real following their 3-1 victory over Liverpool in last month's Uefa Champions League final.
Speaking on Monday at Portugal's World Cup team base camp on the outskirts of Moscow, Fernandes said: "I have nothing negative to say about Cristiano, he looks focused and doesn't look at all worried about his future."
In the aftermath of Madrid's third successive European title in Kiev, Ronaldo said: "It was very nice to be at Real Madrid."
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A day later he struck a more conciliatory tone, telling Madrid fans gathering at the city's Plaza de Cibeles "see you next year", but Portuguese newspaper Record stoked the fire again last Thursday by claiming Ronaldo would definitely be leaving.
It is not the first time he has appeared close to the exit door at Real, often for the same reasons - wrangling over contract negotiations, a frosty relationship with president Florentino Perez, and a perceived lack of support in his row with Spanish tax authorities.
Other commentators speculate that Ronaldo could even be jealous over Madrid's courting of Paris Saint-Germain's Brazilian star Neymar.
