Samu Manoa of the United States Eagles makes a break against Australia at Soldier Field on September 5, 2015 in Chicago, Illinois (AFP Photo/Jonathan Daniel)

Los Angeles (AFP) - The US Eagles have set themselves the ambitious target of reaching the World Cup quarter-finals for the first time as they aim to build on a series of encouraging results for American rugby.

The United States have played in all but one of the previous seven tournaments but have so far never come close to qualifying for the knockout rounds after being eliminated in the pool stage.

Another challenging assignment awaits them in England, where they are lumped in Pool B with two-time champions South Africa, hard-hitting Samoa, Six Nations side Scotland and Asian giants Japan.

Yet the Americans have drawn confidence from the rapid development the game has made in recent years, and coach Mike Tolkin has also had the rare luxury of having his squad in camp for several weeks leading into the tournament.

The US performed well in the Pacific Nations Cup, defeating Canada and Japan while going down in narrow defeats to Samoa and Tonga.

Most recently, the Eagles were beaten 47-10 by Australia in Chicago, but by no means disgraced themselves, holding the Wallabies to 14-10 at half-time.

The rise of talented players such as number eight Samu Manoa and Ireland-born fly-half A.J. MacGinty -- who like legendary Irish centre Brian O'Driscoll went to top Irish rugby playing school Blackrock College -- alongside veterans such as Saracens star Chris Wyles, has also given the US cause for optimism.

Veteran coach Tolkin says the key to success in England will be maintaining performance levels for 80 minutes of a match.

"The first thing, going into a World Cup you want to get out of your group, and that's certainly our over-reaching goal," Tolkin said.

"But a World Cup game is difficult to win. So we're going to take it one game at a time."

"The things we've been focusing on is playing full 80-minute games, not letting our concentration drop at all, keeping pressure on our opposition throughout the match," he said.

"Those are the battles we want to win and if we do then eventually things can fall into place for us."

Tolkin says the US players have improved all round rugby awareness in recent years, which could be crucial.

"I think our defence is really starting to become very mature. We can play different kinds of attack and we know how to deal with them," Tolkin said.

"We're learning to play the game in the right parts of the field."

Where the United States may struggle is in the depth of their squad.

Technically demanding positions such as front row and scrum-half remain problem areas which may expose the Americans in the event of injuries.

Nevertheless, Tolkin is confident US rugby is on the right trajectory.

"When I first started playing and watching rugby, there was no American rugby on TV, you couldn't see the national team play, none of our players were playing overseas, they were all scattered across the country," Tolkin said.

"That's all changed now. We're making great strides -- but there is a long way to go."