What are the tax implications on investing in US stocks and ETFs as an NRI?

What are the tax implications on investing in US stocks and ETFs as an NRI?

You will be taxed as per the laws in the country where you are a tax resident. 
For example, if you are a tax resident of the UAE, you will pay taxes as per the UAE tax laws.

Please note that there is a tax on dividends, which are deducted at the source. Hence if you earn any dividends, the dividend tax will be deducted in the US, and the amount post deduction will be credited to your Vested account under Cash balance/ Buying power.