I submitted a provisional patent application from an foreign country to the USPTO a few months ago. I researched and found out my idea worth a non-provisional patent application. (I made it public.) Is it possible for me or my lawyer, who are not-residents of the USA, to go there to submit a non provisional application with my passport? Or are non-provisional applications to the USPTO office for USA residents only?
There is no residency or citizenship requirement for filing. However, you would be wise to seek the help of an agent or attorney admitted to practice before the Patent Office, and they will likely be a US resident. In particular, there is a recent change to the law that suggests you may want to convert the provisional to a non-provisional within the next few weeks.
Either way, you can file the application electronically without needing to travel to the US.
The link for the USPTO's electronic filing system is here:
The U.S. doesn't care what your citizenship is when you file a patent application (provisional or non-provisional). You could file the non-provisional application yourself but you should hire an attorney to do it as there are many important details.
One very important issue is that your own country might place restrictions on you filing a patent application in another country. Many countries require you to either (1) file the patent application first in your own country or (2) obtain a foreign filing license before you file the application in another country. You may have already broken your own country's laws by filing the provisional application.
You stated that your provisional application is public, but that is not possible until after you file a non-provisional application. You have a misunderstanding in that respect.
Your strategy depends on whether your country is a Paris Convention Member and what your local filing status is. Non-US resident doesn't come into play here - non-provisional patents can be assigned to non residents. Review this article and this "Protecting Inventions Internationally" scenario - then go work with your IP lawyer.