Yes! You can extend your us tourist visa. However, you
need to do so 45 days in advance before the expiry of
your visa. You should file your request to the U.S.
Citizenship and Immigration Services by filling out
I-539 form. However, you must fit the criteria to avail
a visa extension, such as non-involvement in any type of
crime during your stay, non-violation of your admission
conditions, and validity of your passport.