In a Tehran neighbourhood dotted with shops selling football jerseys and sporting goods, 10-year-old Helma was already feeling World Cup fever.

"I'm supporting Iran because it's always the champion!" she said, sporting a bracelet in the green, white and red of the national flag. "This year, it will be number one out of all the countries!"

Holding a shopping bag containing a national team jersey, her mother explained that Helma was set to appear in a video clip supporting Iran's side, adding: "We came to buy Team Melli outfits for the shoot."

But after weeks of war with Israel and the United States -- one of the co-hosts of this year's tournament -- not to mention persistent economic hardship and stuttering efforts to bring the conflict to a final close, not every Iranian shares the grade-schooler's excitement.

At a shop in the same district, 17-year-old employee Houman said Portugal jerseys were the bestsellers, with Spain and Brazil also popular.