It will depend on the contract you have sign with the landlord.
Generally they don't like losing money on the lease and if they don't have a special provision for early lease termination you may be on the hook for money.
There are several options that may be available for moving out early but if you don't want any financial consequences in the US (for example you are looking at some point in the future to move back to the US) most of them require cooperation of your landlord.
The simplest option that is available is you find a tenant that would be willing to sign a lease at the same or higher price for the apartment that you have rented. The landlord will have to agree to it in this case you don't pay any penalties and basically your lease terminates normally on the first of the month and the new tenant moves in.
The more complex option that the landlord has to agree to is subleting or subleasing. Which basically means that the rental agreement remains in your name but the payments are made by someone else it includes rent and utilities (rental insurance you should be able to cancel at any time).
There are uglier options that involve non-payment but I suggest you don't avail yourself of those.