Rice made the comment in Berlin during a joint news conference with German Chancellor Angela Merkel on 6 December.
The U.S. Secretary of State said the United States adheres to U.S. and international laws and conventions that prohibit torture.
Rice also said the administration of U.S. President George W. Bush will use every lawful means to combat terrorism.
"We face an enemy that operates within our societies and that is intent -- intent, not by collateral damage, but intent -- on killing innocent civilians, as they have done in New York, and in Washington, and in London, and in Madrid, and in Casablanca, and in Amman, and all over the world. We have an obligation to defend our people and we will use every lawful means to do so," Rice declared.
Earlier, Rice acknowledged that the United States has flown terrorist suspects abroad for interrogation. However, she denied that the detainees were ever tortured in U.S. custody or knowingly transferred to other countries to be tortured.
Rice said the United States and its allies have cooperated in lawful operations to produce intelligence that has prevented terrorist attacks, including plots that have threatened lives in Europe.