A Potter wasp (ANCISTROCERUS) male drinking nectar on Giant goldenrod (Solidago gigantea).
Male are recognisable by the 13 antennae segments and the yellow clypeus (not visible on these photos).
I suspect this species is A. gazella but the groove in sternite 2 is not clearly visible enough [1].
Literature
1 Determinaties muurwespen (Ancistrocerus) AHW