Here is a timeline of the key events leading up to the signing...

Here is a timeline of the key events leading up to the signing of a landmark nuclear submarine deal between Australia, the US and the UK:

Late 2019 - Scott Morrison tasks defence officials to look into feasibility of acquiring nuclear-powered submarines after doubts over the French contract.

Anthony Albanese (L), US President Joe Biden (C) and British Prime Minister Rishi Sunak (R) in San Diego.

May 2021 - Morrison presents AUKUS proposal to full national security committee and is given permission to approach US and UK leaders with an official government policy.

June 2021 - Morrison meets with US President Joe Biden and then UK prime minister Boris Johnson on the sidelines of the G7 and agree to an in-principle deal.

September 2021 - The deal is publicly unveiled, with Morrison announcing it in Canberra flanked by TV screens of the US and UK leaders. An 18-month consultation period begins into how Australia will acquire nuclear-powered submarines and which model it will go with.

May 2022 - Labor wins the federal election, triggering a change in government.

August 2022 - Defence Minister Richard Marles announced a review into the defence force and how it will tackle emerging threats. The review is to run alongside the AUKUS consultation period.

December 2022 - Marles and Foreign Minister Penny Wong meet with their US counterparts in Washington for the annual AUSMIN meeting.

January 2023 - Australian government finalises submarine pathway.

February 2023 - Australian and UK defence and foreign ministers meet for annual AUKMIN consultation.

February 2023 - Defence force review is handed to the prime minister and defence minister. A government reply is expected in April.

March 2023 - Prime Minister Anthony Albanese, US President Joe Biden and UK Prime Minister Rishi Sunak unveil the path to acquiring nuclear-powered submarines.