Sir, I'm a dutch citizen that has been invited to visit china by my business partnert. I have applied for visa and this was given to me in december. I have a ticket for the the 28th of March I was not able to travel ealier due to several reasons. My Visa will expire on the 27th of march (i just noticed)

Do I need to have a new invitation letter or I can just come to the Embassy for an extension or new visa?

Regards
Kay