Messi says his tears after first goal were caused by personal 'difficult days'

An emotional Lionel Messi was wiping his tears with his shirt after scoring Argentina's first goal against Algeria in the World Cup, a strike that marked the beginning of a memorable performance where he netted thrice to secure a 3-0 win.

But while his first World Cup hat-trick had many Argentine fans in tears of joy, Messi said he was crying for a personal reason unrelated to the sport.

"Why did I cry? It was something completely unrelated to football. I went through some difficult days," said Messi, who is playing in a record sixth World Cup, after Tuesday's match.

"But I'm grateful to the entire delegation and my team-mates because they were always by my side, giving me a lot of strength to help me get through it."

Messi, who turns 39 next week, has equalled Miroslav Klose's record of scoring 16 goals at the World Cup.

Argentina will continue their title defence with a Group J game against Austria on Monday.