According to the bank's chief executive, an overall reduction of ten to 20 per cent was "clearly feasible" in the current climate.
He also suggested that the bulk of the downsizing - which is likely to include significant job losses - would come in Citi's IT and operations wings.
In turn, this would increase the bank's focus on its capital management business.
Mr Pandit's comments come on the day of the bank's first-quarter results declaration - in which Citi is expected to register a loss of around $4.75 billion.
Speaking to Bloomberg, US portfolio manager Peter Kovalski said that the bank chief was "doing what needs to be done".
He added: "The variable [Mr Pandit] has no control over is the global economy, and how much further deterioration there's going to be.''
Citi currently employs around 370,000 people.