The US LLC cannot be formed at the federal level. In the US, LLCs are formed and registered at the state level. The United States provides a lot of independent power to each of the states that make up the United States of America, thus having no centralized system to federally register an LLC.
A LLC doing business nationwide in the US, must register in each and every state. They must first form the LLC in a specific state, and then register it as a foreign LLC in whatever states the LLC will do business in.
In the US, many people form their LLC in Delaware or Wyoming. Both the Delaware LLC and the Wyoming LLC provide minimal reporting requirements and minimal initial listings of information.
The Delaware LLC is more expensive than the Wyoming LLC, but globally, more well recognized because of the marketing the State of Delaware puts forth worldwide. For this alone, many global businesses will decide to form their LLC in Delaware, because their home Country finds the Delaware LLC more acceptable.
For an out of country resident, the LLC will be taxed at the corporate level with the IRS, unless you have a social security number.
To get started, you form the LLC in whatever state you choose, like Delaware. In Delaware it’s called filing a Delaware Certificate of Formation.
After the State of Delaware approves your Delaware LLC, you will obtain an EIN number with the IRS.
That is it. You officially have a US LLC then.
When you make money with the US LLC, you will file your taxes under the LLC as a separate entity because you are not a US citizen. You will need to elect at this time to have your LLC be taxed as a regular corporation and pay corporate tax rates: http://www.irs.gov/publications/p542/ar02.html
The corporate tax rates are the same rates, the biggest of corporations pay in the US. You have no alternative though because you are not able to pay the taxes personally without a social security number. Paying corporate tax rates really isn’t that bad though. It actually is a way simpler way to pay the corporate taxes and keep the LLC a completely separate entity than yourself personally.