The UK and Australia are to work together on framing a bilateral free trade agreement that could come into force following the former's exit from the European Union.
Officials will meet twice a year from the start of 2017 to fast-track trade negotiations between the two countries.
The announcement came after talks between the UK and Australian trade ministers, Liam Fox and Steven Ciobo, in London.
However, Ciobo warned that an Australian-UK trade deal "may be a few years off".
Prime Minister Theresa May has not provided a date for when she will trigger Article 50 of the Lisbon Treaty to formally begin the Brexit process, but it is expected to happen in the first half of 2017.
The BBC says Australia has been earmarked by Whitehall as the UK's first post-Brexit trade partner.
"We have agreed to establish a bilateral trade working group that will focus on scoping out the parameters of a future ambitious and comprehensive Australia-UK free trade agreement (FTA)," Fox and Ciobo said in a joint statement.
"We want the working group to advance an agenda that will ensure the expeditious transition to FTA negotiations when the UK has formally completed its negotiations to exit the EU."
Ciobo told News.com.au: "The fact is, an Australia-UK negotiation of a FTA may be a few years off.
"Your processes to disengage with the EU will take years — years of potential liberalisation we can't afford to let slip. Certainly, none of our competitors will.
"So we're working on an Australia-EU FTA, which will prepare the way for our own agreement in years to come."
Australia is the UK's 21st biggest export destination, with shipments in the first half of 2016 amounting to £1.8bn ($2.4bn).
In comparison, Britain's exports to the US over the same period were worth £22.3bn.
At the weekend, US President Barack Obama played down hopes of a trade deal with the UK being fast-tracked post Brexit.