A little geography I learned while doing some googling this weekend...
the Northern Marianas is a group of 15 islands in the western Pacific Ocean...
they are a commonwealth of the United States... the two largest islands are
Saipan and Tinian... Guam is about 100 miles away, but is a separate US territory.

A Google search reveals several places to play poker, casino games & slot machines
on Saipan: the Imperial Pacific, Best Sunshine, Saipan Vegas, High Roller Poker,
and Piano Poker among them.

Tinian has had gambling in the past (Lone Star, Tinian Dynasty) and there are a couple
of proposed casino/resort developments under consideration, but I don't believe there's
casino gaming on Tinian at this moment. Tinian Dynasty Casino closed down in 2015
after being hit with a $75 million fine for improper money handling.