I think unless it is a well know MBA, it won't be too powerful.
However, it will still count - you will get credit when applying for a job, just won't get any recognition of a value (think of it as a checkmark rather than a plus).
However, if all of your experience is in Greece (worked for a local company, not Nestle or Coca Cola, school, etc), it will be really tough to find a job in the US; US employers prefer to hire from companies they know and familiar with. They prefer someone else to do the vetting and training.
Founder of GMAT Club
Just starting out with GMAT? Start here... | Want to know your GMAT Score? Try GMAT Score Estimator
Need GMAT Book Recommendations? Best GMAT Books
Co-author of the GMAT Club tests
Have a blog? Feature it on GMAT Club!
GMAT Club Premium Membership - big benefits and savings