An American warship is pulling into Darwin with a view to enhance US– Australian relations, with crewmen expected to roam the city in the coming days.

It was also confirmed members of the Royal Australian Navy were on-board the Emory S. Land to develop their knowledge, skills and experience in how their American counterparts conducted nuclear-powered submarine maintenance.

The arrangement to offer submarine-related training to ADF personnel follows Australia’s commitment to bringing into service multiple nuclear-powered Virginia class submarines, expected to patrol Australian waters as early as the 2030s.

The arrival of Emory S. Land coincides with the ramped up military activity currently underway across the Top End, with ADF and Marine Rotation Force – Darwin, integrating at Mount Bundey Training Area.

The lawsuit, filed by the families of Sax, Carlson, Strickland and Rasmuson, accuses Boeing, Bell Textron, Rolls Royce Corps and Rolls Royce North America of negligence, negligent and fraudulent misrepresentation, and the failure to warn.

Tim Loranger, the lawyer representing the families in the lawsuit, told CNN on Thursday that ultimately the lawsuit alleges that the aircraft the Marines were on was known to have a defect but “insufficient steps have been taken to correct it.”

The lawsuit comes months after another deadly V-22 Osprey crash off the coast of Japan, which resulted in the deaths of eight US Special Operations airmen. The US military grounded its entire fleet of V-22 Ospreys in December as a result. That grounding guidance was lifted in March this year; officials said at the time an investigation identified a “materiel failure” responsible for the crash.

Col. Brian Taylor, the program manager of the Naval Air Systems Command V-22 joint program office, told reporters in March that the crash resulted from an “unprecedented” component failure, though he declined to say what component specifically failed or how.

A US Marine appeared in court after being charged with rape, charges he will seek to contest.

The man appeared in the Darwin Local Court on Wednesday charged with sexual intercourse without consent.

He was joined in court by members of his marine corps.

The case returns for a preliminary examination mention on July 3, where the defendant is excused.

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.

The federal funding boost will upgrade bases in the Northern Territory, Western Australia and North Queensland during the coming decade, as part of Defence's pivot towards the Indo-Pacific.

Darwin's Larrakeyah Defence Precinct will be upgraded to berth submarines, but Mr Conroy said Australia's future nuclear submarine fleet would not be based in the Top End.

He said the government was focused on "hardening and developing" bases in the Northern Territory, as well as other installations in northern Western Australia and North Queensland.

"The NT is critical to the defence of the nation, not just in defending Australia but projecting power out into our region against any potential adversary," Mr Conroy said. He said the funding would go towards projects such as surveillance aircraft based at RAAF Tindal, near Katherine, and the purchasing and training of crew for new amphibious landing craft based in Darwin.