On April 20, 2010, an explosion destroyed an offshore drilling rig at the Macondo Prospect in the Gulf of Mexico, causing a major sustained oil leak. The well's operator, BP, initiated a containment and cleanup plan, and began drilling two relief wells intended to stop the flow. Obama visited the Gulf on May 2 among visits by members of his cabinet, and again on May 28 and June 4. On May 22, he announced a federal investigation and formed a bipartisan commission to recommend new safety standards, after a review by Secretary of the Interior Ken Salazar and concurrent Congressional hearings. On May 27, he announced a six-month moratorium on new deepwater drilling permits and leases, pending regulatory review.[206] As multiple efforts by BP failed, some in the media and public expressed confusion and criticism over various aspects of the incident, and stated a desire for more involvement by Obama and the federal government.[207]
In July 2013, Obama expressed reservations and stated he "would reject the Keystone XL pipeline if it increased carbon pollution" or "greenhouse emissions".[208][209] Obama's advisers called for a halt to petroleum exploration in the Arctic in January 2013.[210] On February 24, 2015, Obama vetoed a bill that would authorize the pipeline.[211] It was the third veto of Obama's presidency and his first major veto.[212]