According to U.S. Undersecretary of State William Burns, Iran may be losing as much as $60 billion annually in energy investment. Sanctions are making imports 24% more costly on average. In addition, the latest round of sanctions could cost Iran annually $50 billion in lost oil revenues. Iran is increasingly using barter trade because its access to the international dollar payment system has been denied. According to Iranian officials, large-scale withdrawal by international companies represents an "opportunity" for domestic companies to replace them.