The Strategic Petroleum Reserve (SPR) is an emergency petroleum store maintaine by the United States Department of Energy. The US SPR is the largest emergency supply in the world with the current capacity to hold up to 727 million barrels (115,600,000 m³) of crude oil. The second largest emergency supply of petroleum is Japan's with a 2003 reported capacity of 579 million barrels (92,100,000 m³).