At a news conference on Monday morning, Secretary of State Hillary Clinton called the document leak an attack on America and the international community. She also said the U.S. is taking "aggressive steps" to hold the people who leaked the documents responsible.
The papers contain information about foreign leaders, terrorism and nuclear tensions.
Publication of the secret memos and documents amplified widespread global alarm about Iran's nuclear ambitions. It also unveiled occasional U.S. pressure tactics aimed at hot spots in Afghanistan, Pakistan and North Korea.
The White House has said that the leaked information endangers U.S. diplomats and others.
The Associated Press Contributed to this report.