As the Lower House passed controversial security bills Thursday designed to deepen Japan's military ties with the United States, Okinawa Gov. Takeshi Onaga moved a step closer to halting work on a controversial new U.S. air base after an advisory panel found serious flaws in the approval process.

In a long-expected report, the advisory panel to Onaga, who won election last November by campaigning against a Henoko replacement facility for the U.S. Marine Futenma Air Station, cited concerns about how former Gov. Hirokazu Nakaima approved a central government landfill permit for the project in December 2013.

The report outlined a lack of environmental protection measures in the Henoko Bay area, and said the prefecture approved the landfill project without a sufficient explanation from the Okinawa Defense Bureau, part of the Defense Ministry.