England, top of Group I, are looking to build on their victory over defending champions West Indies in the opener, while Bangladesh are second-bottom after losing to Sri Lanka.
"Winning momentum is vital. The way the tournament is set out, there's not much room for mistakes," Buttler told reporters. "We can take lots of confidence from the first game, it's fantastic to get a win on the board.
"Bangladesh are a strong team... they're a dangerous side. They have some really experienced players in the team and we're expecting a tough challenge.
"Obviously we try and plan for the opposition but at the same time we're focusing on ourselves and get our level of intensity to the place it needs to be. We feel confident as a group when we get that right and... that's going to give us the best chance for success."
Bangladesh fast bowling coach Ottis Gibson said the team remain calm and bring their A game against a "very powerful" England side for Wednesday's match in Dubai.
Gibson, who previously worked with England from 2007-10 and 2015-17, said Bangladesh had a tough qualification route but they are confident of beating strong teams at the world showpiece event.
"We know that England have a very powerful lineup and we know that we have to be on our A game if we're going to really challenge them and ultimately win the game," Gibson said.
"I've spoken to our bowlers and our batsmen... The message is not to panic, understand that you are going to get hit. You might bowl a good ball and get hit because that's their mentality, but they also give you opportunities to take wickets.
"We must try and execute our skills plans. And when those opportunities come, we must take those opportunities."