A U.S. senator on Monday called on President Barack Obama's administration to partly lift the 40-year-old ban on crude oil exports so as to use the strategic assets as political and diplomatic leverage. Lisa Murkowski, ranking member of the U.S. Senate Energy Committee, made the appeal when addressing the IHS CERAWeek conference in Houston, one of the country's top annual gatherings of energy industry leaders. Murkowski, who was the opening speaker at the conference, said she will submit a request to the Energy Information Administration, part of the Department of Energy, for an economic analysis of the potential impact of authorizing exports of crude oil. She laid out a step-by-step plan for renovating U.S. energy policy, including streamlining regulations on condensate export permits and expanding exceptions. After the 1973 oil crisis, the United States imposed a ban on exports of crude oil, with small exceptions for Californian crude, oil from Alaska and sales to Canada. Murkowski argued Monday that energy, long considered as a strategic liability, is now among the nation's strategic assets, which could be used as political and diplomatic weapons to help protect allies and "deal with bad actors from a position of strength." On an aggregate supply-demand basis, the United States is rapidly approaching a self-sufficiency rate of 90 percent in energy, according to Murkowski. She said surging American oil and gas production "needs to go into the political calculation" and become a "strategic asset" for Secretary of State John Kerry as Washington responds to the Ukraine crisis. Crude oil prices climbed about 2 U.S. dollars a barrel on Monday amid concerns that the turmoil in Ukraine could cause disruptions in the natural gas Russia delivers to European countries. Russian is a major supplier of natural gas and oil for the European Union, and most of the EU-bound Russian energy exports travel through Ukraine.