The Government Accountability Office (GAO) report highlighted that offshore facilities increasingly use technology to remotely monitor and control equipment, making them vulnerable to cyberattacks and risking environmental harm and supply disruptions.

"The Department of the Interior's Bureau of Safety and Environmental Enforcement (BSEE) has long recognized the need to address cybersecurity risks but has taken few actions to do so," said the report, which was first published on Oct. 26 to certain members of the U.S. House of Representatives who requested it.

A successful cyberattack could wreak damage resembling the effects of 2010 Deepwater Horizon disaster, the report said. That disaster was not a cyberattack but it killed 11 workers and cost billions of dollars for Gulf Coast restoration. The report mentioned China, Russia and Iran among actors that may pose significant threats.

(Reporting by Seher Dareen and Deep Vakil in Bengaluru; Editing by Matthew Lewis)