Radionz - Guam football coach Gary White says there's no time to let up despite a fairytale start to their World Cup qualifying campaign.

The US Territory defied their lowly ranking of 174 by winning back to back games, against Turkmenistan and India over the past week, to go top of Group D in the second round of Asian qualifying.

Their next match is a daunting trip to the Azadi Stadium in Tehran in September to face four-time World Cup finalists Iran.

Gary White says it's an exciting test for his players.

"We've got to now prepare for a different opponent - a very very strong opponent in a very very hostile environment. It's just another level to see where we are in world football and I don't think there's a better way of doing it than measuring yourself against the best".