(Bloomberg) -- UK Prime Minister Rishi Sunak and his Australian counterpart, Anthony Albanese, are planning to go to Washington DC in mid-March potentially to unveil a proposal for Australia’s nuclear submarine project, according to a person familiar with the matter. 

Under plans still being thrashed out, President Joe Biden could host the British and Australian leaders, and the allies are expected to announce their preferred design to replace Australia’s aging Collins-class fleet, according to the person. 

The three nations are sharing classified military capabilities to allow Australia to construct and deploy new nuclear-powered submarines in the Pacific region. The project is part of the the so-called Aukus agreement, launched in 2021 as a trilateral alliance to counter Chinese military power in the Pacific.

Australia’s federal parliamentary schedule means Albanese could travel between March 10 and 19, while Sunak’s government’s budget statement on March 15 means he is unlikely to leave the country immediately beforehand. 

Sunak’s office said a visit to the US is possible, but said no date had been set and would not confirm any reason for the visit. Neither Albanese’s office nor the White House responded to requests for comment.

Max Blain, Sunak’s spokesman, declined to comment on the plan when asked by reporters in London on Thursday. 

The project has taken longer than expected, with US restrictions on technology and information-sharing applying to the other Aukus members even though they are partners in the Five Eyes intelligence-sharing community. The announcement of the pact also upset France in 2021, which saw project to build non-nuclear submarines with Australia ditched as part of the new alliance.  

Closing a two-day visit to the UK by Australian Defence Minister Richard Marles and Foreign Minister Penny Wong, Marles said he’d witnessed the closeness of the two nations working together. 

“That, in a larger sense is clearly happening in its most profound way through the United Kingdom and United States working with us through the architecture of Aukus to help Australia acquire nuclear-powered submarine capability,” Marles said at a news conference in Portsmouth, southern England.

UK Defence Secretary Ben Wallace, speaking alongside Marles, said “a range” of options on the submarines are available for discussion by Australia’s cabinet. “Whatever option is chosen by Australia, it will be collaborative,” with the UK and US, he said.   

--With assistance from Ben Westcott.

(Adds comment from Australia’s Marles in eighth paragraph)

©2023 Bloomberg L.P.