"My end point is Russia, there's nothing after that," Mascherano told Argentina broadcaster TyC Sports.
Argentina beat Ecuador 3-1 on Tuesday to clinch a place in Russia in a must win match for the underperforming side.
The two-times champion reached the final in Brazil three years ago, losing to Germany in extra-time, while they also lost the finals of the 2015 and 2016 Copas America.
However they struggled in the qualifiers and needed a hat-trick from Lionel Messi to get them to Russia.
The 33-year old Barcelona defender, who sometimes plays in midfield, said the opportunity to win a major title for his country was one of his last remaining playing ambitions.
"I don't have that many things in my life I still want to do," he said. "Playing in a World Cup and trying to get back to the final is one of them."
(Reporting by Andrew Downie; Editing by Greg Stutchbury)
