Barcelona president Josep Maria Bartomeu has told ESPN FC that star player Lionel Messi has a contract with the club "forever" as they prepare for negotiations on a new deal in the coming months.

Messi, 29, has a contract which currently expires in June 2018. However, this summer, the Argentine star was linked with a possible move to re-join former boss Pep Guardiola at Manchester City, as well as a return to his childhood club Newell's Old Boys following the 2018 World Cup, something Messi said he would "love to do."

But Bartomeu has made renewing Messi's deal a priority this term.

"[Messi] has all the years he wants [with Barcelona]. Lionel Messi is the best ever to play football in the history of the world and he plays with us," he told ESPN FC in an exclusive interview. "We are very happy, he is very important for the club, he's very important for the fans, he's very important for football itself.

"And Lionel Messi in the next coming months of course we are going to talk with him because he knows, he already knows that he has a contract forever. There is not a limit with him.

"The limit will be decided by him and right now he is 29 years old, he is talented, he is ambitious, and he's in perfect shape to continue for many more years."

Lionel Messi aggravated a groin injury against Uruguay and there is no timetable for his return. Gabriel Rossi/LatinContent/Getty Images

Bartomeu went on to say that he expected negotiations to be complete shortly, adding: "For now, we think we will do it in the next coming months, but Leo Messi will continue in Barcelona, of course."

Messi returned to international competition with Argentina last week after a brief retirement from the national team following this summer's disappointment at the Copa America Centenario.

He helped lead his country to a 1-0 win against Uruguay, although he aggravated a groin injury near the end of the match and didn't play in Argentina's 2-2 draw with Venezuela on Tuesday. Barcelona have yet to offer a timetable for his return.