If a cop stops you and wants to talk, and you choose to do so, that's your choice. You don't have to stop, much less talk, unless he uses the magic words, "you're under arrest." Best to take the position of Bartleby the Scrivener, "I prefer not to."
If the cops have probable cause necessary to arrest you, they are going to do so. You have no rights under Miranda v. U.S. unless and until you have been subjected to an arrest. So talking to them prior to an arrest is a waiver of your rights, and you cannot be required to waive your rights. Talking to them will give them probable cause if they don't have it already, and whatever you say can, and will, be used against you in court (though it'll be called "a confession" or "an admission" when you're in court).
Like the old song, "If you see me walkin' down the street... walk on by; just walk on by." If you must say something, let it go with "Good morning, officer, lovely day we're having, isn't it?", except in the one case in which you are challenged with a statement of fact to which one would normally expect a denial (the failure to deny such a statement can, in some situations, be treated as an admission), such as "You used that gun in a murder." Regardless of how long or challenging such a remark might be, the appropriate response is, "hogwash." -- keep walking.
Identification: unless you're engaged in an activity for which licensure is required, and for which the certificate evidencing licensure must be produced upon demand (e.g., fishing, driving, acting as a private investigator, etc.), you never have to produce any documentation showing who you are. There is authority for the proposition that you must inform an appropriate law enforcement officer of your name and address, when you're about in the night-time.
Otherwise, "walk on by."
