Universal Jurisdiction Rejection Act of 2003 - Declares that it is the policy of the United States to reject any foreign government's claim of universal jurisdiction and to refuse to assist any such government pursuing an investigation or prosecution under a universal jurisdiction act. Defines "universal jurisdiction act" as a statute of a foreign country that authorizes the investigation, prosecution, and punishment of genocide and other crimes that were not committed by or against citizens of such country, did not occur on the territory of such country, and are otherwise prosecutable by tribunals established by the United Nations Security Council.
Prohibits Federal, State and local government agencies, including any courts, from providing assistance to any investigation or prosecution by a foreign government under a universal jurisdiction act. Directs the Federal Government to exercise its rights under mutual legal assistance treaties to deny assistance to any investigation or prosecution under a universal jurisdiction act. Prohibits foreign agents from pursuing any investigation or prosecution under a universal jurisdiction act in the United States.
Directs the President to ensure implementation of procedures to prevent the transfer directly or indirectly of classified national security information to foreign governments that is relevant to any investigation or prosecution under a universal jurisdiction act. Allows the President to waive certain prohibitions under this Act.
Authorizes the President to use all means, including legal assistance, but not financial incentives, to secure the release of U.S. citizens and citizens of allies of the United States who are being detained or imprisoned by an investigation or prosecution under a universal jurisdiction act.