What is my tax obligation as a non resident alien while waiting for EB-5 approval?

Tax residency applies along a different timeline than immigration residency, and chatting with an internationally experienced accountant will be really beneficial.

A non-resident alien is defined by the Internal Revenue Service (IRS) as someone who is not a green card holder or someone who has not passed the substantial presence test. Both of these terms are defined by the IRS and available for review on their website. An individual with a pending I-526 who is not present in the U.S. and is residing abroad has unlikely triggered any U.S. liability if they have not been present in the U.S. for significant periods of time. Once an individual becomes a lawful permanent resident, U.S. tax obligations will commence. I recommend obtaining professional taxation advice to address your personal situation.

Best to check with a tax attorney.

You can be subject to worldwide taxation either by having a green card or by being physically present in the U.S. for a certain period of time.

The situation of each individual is different. I would suggest you consult a U.S. CPA about your tax questions.

This is exactly the reason why we always advise our clients to seek a consultation from a tax advisor/consultant (not just a CPA) as they go through the source of funds process. Among other things, your answer depends on whether you are considered a tax resident for U.S. tax purposes, how much time you have spent in the U.S., and etc. It is impossible to answer your question without knowing more about your specific situation.

This is a question you should direct to an accountant.