Argentina have no room for error after their sensational defeat in the FIFA World Cup

Lionel Messi says that his side have no one to blame but themselves after his Argentina team were stunned by Saudi Arabia in their opening game at the FIFA World Cup in Qatar, snapping a 36-game unbeaten streak in the process.

Messi's fifth - and likely last - World Cup suffered the most ignominious start imaginable after his first-half penalty was canceled out by two Saudi Arabian strikes within five minutes early in the second half, in what is being considered one of the biggest upsets in World Cup history.

But speaking after the dispiriting defeat, Messi said that he was well aware of what Saudi Arabia, a team 48 places lower than them in the world rankings, were capable of.

"We knew they were a team who would play if we let them ... They did not surprise us, we knew they could do that," the Argentine icon said via Todo Noticias.

"It's a situation that this group of players has never been through, it's been a while since we suffered such a tough blow, we didn't expect to start like this," he added.

Argentina came into the tournament as one of the favorites to win what would be their first World Cup since the Diego Maradona-led triumph in 1986, but the 2021 Copa America winners now face a challenge just to emerge from what has become a very competitive Group C.

And Messi puts the defeat down to those crucial few minutes in the second half during which Argentina let its guard down.

"In five minutes of mistakes that we made, we went 2-1 down and then it was really tough and we lost organization and started punting the ball," he explained.

"Obviously we have to win or win now. It's up to us to fix what we did wrong and get back to the basics of who we are.

"We're okay, obviously hurt by the result, very bitter. But people must trust that this team will not let them down and we are going to go for it in the next two games. We've played games of this nature before and we're going to perform well.

"Now's the time to be more united than ever, to show how truly strong we are."

Messi and Argentina will have an opportunity to correct their errors in their next Group C fixture which comes against Mexico on Saturday - but with little margin remaining for error, it is now a do-or-die situation for one of football's most accomplished players in his World Cup swansong