Japanese officials have made their first public pitch to win a lucrative Australian shipbuilding prize, claiming their Mogami frigate is faster, stealthier and better suited to operate alongside the United States than a rival warship offering from Germany.

Last month, Japan's Mitsubishi Heavy Industries (MHI) and German shipbuilder ThyssenKrupp Marine Systems (TKMS) beat companies from South Korea and Spain to be down-selected for Australia's $10 billion general purpose frigate (GPF) program.

Australia is now assessing whether to buy an upgraded and larger version of Japan's Mogami 30 FFM, which is yet to enter service, or to instead select a variant of Germany's smaller MEKO A-200, which is already operated by the Egyptian navy.

Under the SEA3000 project, the Royal Australian Navy wants to quickly start acquiring overseas-built warships from 2029 to replace the aging ANZAC-class fleet, before eventually transferring the build to the Henderson shipyard south of Perth.

In their first interview since the down selection in November, officials from Japan's Ministry of Defence have talked up mutual strategic ties and assured Australia they could easily transfer warship technology despite a lack of naval export experience.

Representatives from the Acquisition, Technology & Logistics Agency (ATLA) say their upgraded 4,800-tonne Mogami shares many of the design features of its 3,900-tonne predecessor and can travel at a speed of 30 knots, faster than the rival German MEKO.

The newer Mogami also incorporates a 32-cell Mk41 vertical launch system for US-made weapons and is equipped with more modern sensors and radar than the MEKO, which Japan believes will make it more interoperable with both the US and Australian navies.

"I believe that it is beneficial for all of us if like-minded countries can work together because those countries share the same common values," said ATLA official Koji Nishimura, who argued MHI had already worked with the American Aegis Combat System.

"MHI served as a prime shipyard, so it already has a track record of building combat vessels — and in that project, MHI served as a system integrator and accumulated the technology and the technology was shared with the US counterpart," the director of ATLA's Project Management Division for Naval Ships told the ABC.

During trilateral talks in Darwin last month, Japan's Defence Minister Gen Nakatani hailed what he described as his country's "quasi alliance" with Australia, while his host, Richard Marles, praised the Mogami as an "impressive" and "very capable platform".

Despite Japan never having exported warships to a foreign customer, ATLA official Satoshi Ishihara believes his country's proposal can succeed because it is strongly backed by the government and MHI is able to construct 12 ships at a time in three separate shipyards.

"MHI has 120 years of history with shipbuilding and has worked with the Ministry of Defence for almost 120 years, and this company has always respected time and budget with contracts and never delayed a delivery," the director of the Mogami Project Office told the ABC.

Numerous Australian defence and industry figures have suggested that Japan's proposal for the general-purpose frigates was the most expensive of all five original bidders, but ATLA is pushing back by arguing its warship is more durable.

"It seems like the life cycle of German ships is just 30 years — but Mogami can be in service for 40 years at least, so in terms of cost, you can enjoy our service 10 years longer, and in this sense, Japan's ships are not more expensive than German ones," Mr Ishiha said.

"We want to raise the capability level of West Australia's shipbuilders, so MHI is going to take the lead and transfer knowledge, but also at the same time the project involves the development of shipbuilders in Western Australia," Dr Nishimura added.

"The upgraded Mogami is built in a way that makes it easy to customise depending on the owner's order — the power setting and the space design are different from the original one, so the ship is ready to cater to any requests coming from the Australian government."

Following the disappointment of its failed bid for Australia's Future Submarine project in 2016, Japan has recently formed a dedicated task force or "war council" for the frigate contest, led by the country's vice-minister for defence and the president of MHI.

"From the very first phase of the project, I thought about the benefit for Australia and for the Japanese Maritime Self-Defence Force, because of that we formed an all-Japan team — with Ministry of Defence working as a team to make this project happen," Mr Ishihara said.

Andrew Greene travelled to Tokyo as a guest of the Foreign Press Centre Japan.