The defending champions have lost two of their first three matches in India.
England were thrashed by New Zealand in their opener before getting their campaign on track with a win over Bangladesh. They were then stunned by Afghanistan, however, and sit fifth in the standings with only the top four advancing to the semi-finals.
Mott said it was "nowhere near the start" they were hoping for but with six games to play in the group they are not panicking yet.
"The effort is important and I think that's there, the boys are trying really hard," Mott told reporters on Tuesday.
"But we're probably missing that confidence to puff your chest out, go out there and really take the game on, which this team has been renowned for over a long period of time. You don't lose your ability overnight, but you can lose your confidence.
"We pride ourselves on putting the opposition under pressure and on reflection we've been the reactive team in those two games, we need to turn that round really quickly."
England have been playing without Ben Stokes as the allrounder nurses an injury and Mott said the 32-year-old, whom he described as their "spiritual leader", could return for their next game against South Africa on Saturday.
"He certainly spoke really well the other day and spoke about that need to really assert ourselves," Mott added.
"I talked about the plan going forward for the next few days and then Stokesy came in on the back of that and just really reinforced what was a great message.
"I think it went down well, it brought us back to controlling what we can control really."
