England assistant coach Mike Catt said it is "all or bust" for his side and Wales, as they prepare to face-off at the Rugby World Cup in London.

Pool A favourites England and Wales will go head-to-head in front of a bumper crowd at Twickenham on Saturday, after both nations opened their World Cup campaigns with victories.

England claimed a 35-11 bonus-point victory over Fiji in Friday's curtain-raiser, while Wales dismantled Uruguay 54-9 two days later in Cardiff.

The top two nations of each pool will advance to the quarter-finals and Saturday's blockbuster encounter will go a long way in determining the makeup of the last eight, with Australia also in the group, and England's Catt is relishing the upcoming battle.

"We need to make sure that defensively we are able to stop the big threats. We will make the final decision [on the team] on Thursday," Catt told reporters.

"We are massively excited about this. It is what the World Cup is about. It is the biggest game that a lot of the guys have ever played.

"It is all or bust for us and for Wales. They came very close four years ago [reaching the semi-finals] and they won't let these opportunities slip. They are going to throw absolutely everything at us and vice-versa.

"The crowd against Fiji were incredible. If we can have the same support against Wales, it will be massive for the team."

Catt added: "There are certain areas we need to work on but it is a good start. Certain individuals will be disappointed with their performances, but come Thursday, Friday, Saturday, there is a lot of experience now so that they can pull each other through. 

"The whole bench came on and made a huge impact."

Sam Burgess was one of those players to make an impact off the bench against Fiji, and the code-swapper is now in contention to start on Saturday.

The rugby league convert produced an impressive 19-minute cameo in the English capital.

"What we saw against Fiji we've seen all along from Sam," Catt said. "We know what he brings.

"We back Sam. Sam's job on Friday was to come off the bench and cause the opposition problems and that's exactly what he did. He's a big-game player and a great competitor."