'Profound strategic shift'
The pact, which will also see the allies share cyber capabilities, artificial intelligence and other undersea technologies, was described as showing "profound strategic shifts" by the UK's national security adviser Stephen Lovegrove.
It means Australia will become just the seventh nation in the world to operate nuclear-powered submarines.
Mr Lovegrove said the pact was "perhaps the most significant capability collaboration in the world anywhere in the past six decades".
