As a US citizen or green card holder, you are required to report all your world-wide income and pay US tax on it. The only exception is if you are out of the country for at least 330 days of the year, you may be able to exclude foreign income earned from working.
You do get a tax deduction or credit for foreign taxes you paid on the same income. One place to access this is on the page for "Deductions and Credits", go to the section for "Estimates and other taxes paid" and look for "Foreign taxes." If using Turbotax online, you may have to select "show me more options" or "let me choose what to work on".
