The US military could be waiting until next year for the handover of 11 fuel storage tanks currently under construction at Darwin’s East Arm.

Originally scheduled for completion last September, the opening was put back until this July but with just weeks to go, construction flaws and permitting issues continue to dog the $270m development.

The liners beneath the tanks are leaking, environmental permits remain in limbo and building certifications are unresolved.

A spokesperson for the Department of Infrastructure, Planning and Logistics, which has carriage over certification, said under the Act, a building permit was required before work starts, and work must be certified or approved at the end of construction before occupancy.