The buyout clause for the new deal was set at 700 million euros, according to a statement from FC Barcelona.
The contract was first announced
in August, just days after the record-breaking Messi married his childhood sweetheart, Antonella Roccuzzo
"I'm happy to continue with the club, which is my home," Messi, 30, told Barça TV on Saturday, according to the club's website
. "My dream was to finish my career at Barça, and we are moving down that path."
"The objective is to continue achieving things, fill the club's trophy cases and keep making history at Barça," said Messi, who spent his first 14 years in the sport with Barcelona's first team. We've been lucky enough to have won a great many things and I hope there will be more in the future."
Josep Maria Bartomeu, the president of FC Barcelona, posted his praise for the deal on Saturday.
"We are in luck with the Barça players," he wrote. "We continue to enjoy the best player in the history of football."
Standing about 5-foot-7, Messi has been one of the most creative ball-handlers and scorers in world soccer history, and he is FC Barcelona's all-time leading goal scorer.
His partnership with Barcelona has been hugely successful for both sides. Messi has won the Ballon d'Or award, given annually to the world's best player, a record five times. And he has led FC Barcelona to eight La Liga titles, four Champions Leagues, five Copas del Rey, and a slew of other titles.
Forbes estimated that Messi
took in $80 million in earnings last year, making him the third-highest paid athlete in the world.