Are the United States Medical Licencing Exam USMLE results normalized
to different regions? In other words, Does a high USMLE grade from a
test site in the middles east reflect a higher performance amnong test
takers in that region only ?
I am planning to take the exam in the middle east, would that affect
my score in any way?

As far as I am aware, regions have nothing to do with the scoring
process for the USMLE. Each individual candidate will have a different
exam to the next (as the exam is all computer generated), so each
individual candidate score is technically already 'weighted' based
upon the relative difficulties of the questions asked to that
individual. The exam is a universal one, with, say, a candidate from
the Middle East theoretically just as likely to receive a particular
question as a local US candidate. The scoring process is complex,
however there is no regional scoring bias/weighting mentioned in the
USMLE materials.

That said, it's worth noting that non-US candidates tend to do worse
than local US grads. That's probably because many are older (already
qualified doctors) and have subsequently allowed longer to pass since
they learnt their basic sciences and did basic clinical exams. Also,
US students are taught the material for the USMLE as part of their
training - courses outside of the US are, naturally, tailored for
future doctors of that particular country rather than the US.

Hope that helps.