you have to be a little more clear than "just an arrest warrant"
many people think of it that way but there are very different types of "arrest warrant"
if it is what is called a bench warrant. that means they are not actively looking for you, probably a lower crime, not extraditable someitmes not even counties in the same state will find this one. basically if thye stop you in the warranting county you will get taken in.
if you have an active "arrest warrant" as in you did an actual crime, I personally would not be going into any gov't offices where the US has extradition. that's just me though.
if it's child support, I believe that one is an active warrant but not sure they would extradite from another country, however I would not put it passed them. WI will go after child support warrants quite actively.