For the longest time, the US Census Bureau said that Arabs and Iranians were white, so I would say that their definitions are not definite.
Pacific Islanders are pretty much considered Asian also.
I respectfully disagree. Having traveled to many of these islands, courtesy of Uncle Sam's Navy, I can assure you Guamenians, Fijians, Tongans, Samoans and many other such people spread in the Pacific do not consider themselves Asians in any way or form. Especially those that were occupied by the Japanese in WW2.