As part of the naturalization ceremony, you are required to take the Oath of Allegiance. Here it is:

"I hereby declare, on oath, that I absolutely and entirely renounce and abjure all allegiance and fidelity to any foreign prince, potentate, state or sovereignty, of whom or which I have heretofore been a subject or citizen; that I will support and defend the Constitution and laws of the United States of America against all enemies, foreign and domestic; that I will bear arms on behalf of the United States when required by the law; that I will perform noncombatant service in the armed forces of the United States when required by the law; that I will perform work of national importance under civilian direction when required by law; and that I take this obligation freely without any mental reservation or purpose of evasion; so help me God."

In some cases, the Immigration and Naturalization Service (INS) allows the oath to be taken without the clauses: