The Obama administration will not rely solely on the laws of Iran, Iraq, Syria or Sudan in determining who is a dual national and thus ineligible to travel to the U.S. without a visa, a senior U.S. official told POLITICO on Wednesday.The official's comments came as members of the administration faced withering criticism from Republicans during a House committee hearing for carving out exceptions for journalists, business leaders and others under a new law covering the Visa Waiver Program.The visa waiver program has historically let citizens of 38 countries, most of them in Europe, visit the U.S.