More famous for its sun-kissed beaches and coral reefs than its football, the tiny Pacific island of Guam is making waves in Asian qualifying for the 2018 World Cup.

Coached by Englishman Gary White, Guam have put the rugby-score losses of the past behind them with some giant-killing performances and face Iran on Tuesday determined to preserve a remarkable unbeaten home record.

"Mathematically we're still in it," White told AFP by telephone on Monday, defiant despite last week's disappointing 1-0 defeat by India.

"We need to get a minimum of four points from the next two games to have a sniff but in football anything is possible. This is not an easy place for anybody to come. We've won two and drawn one at home so we want to try to keep it as a fortress."

He added: "We've already achieved one of our team goals by reaching the final round of 2019 Asian Cup qualifiers, which is an amazing achievement."

Guam's population is just 170,000 but White's "Matao" -- a name derived from the noble classes of Micronesia's ancient Chamorro society -- have consistently punched above their weight, with victories against Turkmenistan and India, a country of 1.2 billion.

By far the smallest of Asia's 47 national and territorial teams, the state of football in the tiny United States territory was so precarious barely a generation ago that the islanders did not even bother entering the World Cup qualifiers.

And when they did, they would often lose in an avalanche of goals.

Before their 1-0 victory over Turkmenistan at home in June, the last time Guam played a World Cup qualifier was in 2000 against Tajikistan when were hammered 16-0. Three days earlier, Iran smashed 19 goals past them.

"We're not going into games to sit back and hope we don't get beat by 10," said White, who took charge of Guam in 2012. "That's not how the game's supposed to be played."

Top of Group D after their first two games, a 6-0 defeat in Iran brought Guam down to earth with a bump before they held Oman to a goalless draw. Narrow defeats in Turkmenistan and India saw White's side slip to fourth on seven points from six games.

"The only way to approach it is to go for it," said the 41-year-old, looking ahead to Tuesday's rematch with Iran. "I'd prefer that if we are going to go down, we go down fighting -- rather than sitting back and being cowardly."

White, who formerly played for English non-league club Bognor Regis, began coaching in 1998 when he was living on a council estate in Luton, north of London, and faxed every national association in the world looking for work.

After spells with the British Virgin Islands and Bahamas, White has worked a minor miracle on the palm-fringed honeymoon island of Guam, located 1,600 miles (2,600 kilometres) south of Japan.

"A lot of coaches come into these environments and look at it as an obstacle. I look at it as a benefit," said White, whose methods have helped tease some sparkling form from captain Jason Cunliffe and winger Ryan Guy.

"You have to find something that pulls at the heart strings of a country and its culture and history, you can utilise that because it's bigger than anybody," he added.

"We use the Chamorro background, the deep history of Chamorro people, who have been here for thousands of years and survived numerous takeovers from other countries, whether it's the Spanish or the Americans."

At 155th in the FIFA world rankings, Guam will look to psyche out Iran, Asia's top-ranked team at 43rd, before a ball has been kicked when they perform the traditional "inifresi" war cry, the island's version of the New Zealand haka.

Win or lose, White's team have already left their mark on the World Cup qualifying competition.

"What's funny is the fact that a country of 170,000 people went to a massive country like India with a population of 1.2 billion and were completely devastated because we lost 1-0," said White. "That really shows exactly how far we've come."