KITTERY — A new government report says the Navy has fallen short of funding for modernization work at the Portsmouth Naval Shipyard and three other public shipyards.

Maine U.S. Sen. Susan Collins says the Government Accountability Office report examines the Navy’s backlog of modernization and restoration projects at the four public shipyards, including the Kittery facility.

The report says the Navy’s estimate of a $3 billion shortfall in modernization of the shipyards, including $513 million at Portsmouth Naval Shipyard alone, underestimates the actual backlog.

The report was requested by Collins, a Maine Republican, and other members of Congress. Collins says the report confirms what’s been known for a long time.