Argentina in shock after Barcelona announce Lionel Messi's departure

Star forward was expected to sign new contract after previous deal expired in June

A fan wearing a jersey of Barcelona's Argentinian forward Lionel Messi at the Camp Nou after news that the star player will end his 20-year career with the club.

FC Barcelona's supporters gather in front of the entrance of the Camp Nou on Thursday.

Supporters gather in front of the Camp Nou after it was announced that Lionel Messi will end his 20-year career with Barcelona.

Supporters gather in front of the Camp Nou stadium in Barcelona on Thursday evening. Lionel Messi will end his 20-year career with Barcelona after the Argentine superstar failed to reach agreement on a new deal with the club.

Barcelona's supporters gather in front of the Camp Nou.

Members of the media outside Barcelona's offices.

Barcelona's supporters gather outside the team headquarters.

Supporters outside Barcelona's offices.

There was disbelief in Argentina after it was announced late on Thursday that superstar Lionel Messi was leaving Barcelona.

A month after the Rosario-born superstar led the national team to their first major title in 28 years, Messi was again the centre of attention as the club announced he would end his 18-year relationship with them and not sign a new playing contract.

Barcelona released a statement confirming Messi had formally left the club.

"Despite having reached an agreement between FC Barcelona and Leo Messi and with the clear intention of both parties to sign a new contract today, it cannot be formalised due to economic and structural obstacles (Spanish LaLiga regulations)," the statement read.

"As a result of this situation, Messi shall not be staying on at FC Barcelona. Both parties deeply regret that the wishes of the player and the club will ultimately not be fulfilled.

"Barca would like to thank with all its heart the player's contribution to the enhancement of the institution and wishes him the best in his personal and professional life."

Less than a month after the six-time Ballon d'Or winner inspired his country to end their 27-year wait for a major international title in a 1-0 Copa America final victory over Brazil, Messi's homeland was left stupefied.

"It is the end of a unique and undoubtedly unmatchable legend," wrote sports newspaper Ole.

"One of the most beautiful stories in world football is ending: the day we never imagined has finally arrived," added Ole in a tweet.

Newspaper La Nacion said this "unexpected turn" of events was "a bombshell that has shaken world football."

Television channel TyCSports said the news was "difficult to believe" in a tweet, adding that it was "the end of an era that has forever marked the history of football."

The hashtag "Welcome Leo" started trending on Twitter as mock up pictures of Messi wearing the jerseys of domestic giants Boca Juniors, River Plate, Newell's Old Boys and San Lorenzo appeared, as well as more modest outfits such as Sacachispas FC.

The local media, though, took an instant interest in where Messi, 34, will really end up next.

"Global shock .... will Paris Saint-Germain be his new club," said newspaper Clarin, speculating that the French Ligue 1 club was "the main candidate to add him to their galacticos" including Kylian Mbappe and Neymar. "Messi is in his prime and with his sights set on the World Cup, that's why he is continuing to bet on European football."