The agreement was struck in an attempt to increase the influence of the Western allies in the Indo-Pacific region – shorthand for having a greater military presence to counter China in the region.

Auku’s first so-called “pillar” is the cooperation around nuclear submarines. The second is to develop next-generation technology such as artificial intelligence.

Other Indo-Pacific allies nervous about China’s growing geopolitical power, such as Japan and South Korea, have been formally invited to participate in the second “pillar.”

The idea that Japan would at some point formally join the entire pact is so widely speculated that it has even been given its own acronym in the Ministry of Defense: “Jaukus.”

But the prospects do not seem imminent. One obstacle would be that Australia, the UK and the US are all part of the Five Eyes intelligence-sharing network, but Japan is not.

Sir Keir is expected to discuss Aukus with Trump at their first meeting, which will come sometime after Trump is inaugurated on January 20.