Consider that in most states you are not required to furnish identity documents on demand, (unless you are being arrested, or pulled over in a traffic stop) what is the status or required level of compliance expected under the law if a police officer says they need to see your ID?
In other words, in the absence of the officer articulating a crime you are suspected of committing and a clear reason why providing ID is required, does simply repeating the word "need" constitute a request, or a lawful demand?
Of course it is always legal for them to ask you, for you to ask them to clarify, and if they demand it under color of law in no uncertain terms you should consider it a lawful order and comply unless you want the situation to escalate...
However, if they refuse to clarify that you are being detained for suspicion of "X" and just stick to the script that they need to see it, would you be within your rights to consider it a request and refuse to comply? Because what does their unspecified need have to do with anything?
Note: Here are a couple similar questions, but neither address the specific legal meaning of the word "need": NY request for ID, TX request for ID