The heavyweights clash in Mumbai on Saturday, with the two teams licking their wounds from setbacks that have put a dent in their semi-final hopes although England have Ben Stokes back.
It makes the fixture crucial for both to recover and get their campaign back on track, with the loser facing a potentially uphill battle to make the final four.
"We have moved on and had some good conversations and the energy and hunger around practice has been very high," Buttler told reporters on Friday.
"They (South Africa) have been playing some really good cricket, their top six is really strong and they have pace with the ball. Both teams like (to face) pace on the ball, so it should really be a fascinating contest."
England will welcome the return of all-rounder Stokes, who missed their opening three World Cup matches with a hip injury.
"Ben has trained really well and it is always good to see him back. He brings a lot on the field with his presence and leadership skills. He is always someone to turn to and adds a lot of value," Buttler said.
The way forward for England is to be positive with bat and ball, says Buttler, and play the style of cricket that won them the World Cup on home soil in 2019. The conditions in Mumbai should allow for that.
"It is a fantastic cricket wicket, so it should suit us," he said.
"We want to find ways to make a play and put the opposition under pressure. That doesn’t always mean hitting fours and sixes. It means can we push back when the opposition is on top and take the initiative in different ways.
"We know we won’t always win but if we can stick to the way we like to play cricket and get the best version of that, we know that is the best chance we have of getting a positive result."
