You have an approved project that is about to begin - the project team is in place, the product owner has been identified - the stakeholders are eagerly waiting to see results of this agile approach that they have all heard good things about ...
Here's your dilemma ... the stakeholders are expecting to see tangible progress at the end of the first iteration in two or three weeks - having been through presentations of Agile processes. But you know that it's really not feasible to deliver anything remotely useful in that short a period. Agile processes warrant early delivery of business value, stressing on working code. Release planning and iteration planning are all based around user stories completed to the extent of being ready to deploy. But the reality is often different.