The Western Australian town of Wagerup and central hub of Alice Springs will be the first sites to see jointly US-Australian funded critical minerals facilities.
Australia will step up production of the much-needed resources following a pact signed by Anthony Albanese and Donald Trump in the White House on Tuesday morning.
Mr Albanese said the deal would see "an accelerated pipeline of priority projects" with a $1.5 billion investment from both countries to secure a supply chain.
It was possible, Mr Trump said, after fast-tracked negotiations over the past four of five months.
"And it was good timing, and we got it done just in time for the visit," the US president said.
"In about a year from now, we'll have so much critical mineral and rare earths, and you won't know what to do with them."
Minerals Council of Australia chief executive Tania Constable said the deal would "unlock" $13 billion worth of production.
"This is an acknowledgement of Australia's strategically important role in the development of new technologies, defence capabilities and renewable energy infrastructure that stem from the nation's array of critical minerals," she said.
The value of rare earths companies listed on the stock exchange have boomed in recent months given their coveted status.
Arafura Rare Earths' share price was 19.5c at the start of the month and has more than doubled to 48c, while Lynas Rare Earths could be bought for $14.63 a month ago - now they are $20.51.
First up under the pact will be the provision of gallium through a new facility co-located in WA's Peel region alongside Alcoa's Alumina Refinery.
Gallium, used for defence and semiconductor manufacturing, is a critical mineral produced while making alumina from bauxite, as Alcoa does there.
Alcoa said it would aim to bring production online next year, with expectations of 100 metric tons produced each year - or up to 10 per cent of total gallium supply - eating into a market dominated by China.
"Alcoa has been a strong contributor to both the American and Australian economies and welcomes the opportunity to support both nations in progressing a new source of gallium," Alcoa president William F. Oplinger said.
Australia will invest an initial $306 million in the facility, which Japan is also co-funding.
In the Northern Territory, the US and Australia are backing the Arafura's Nolans project, around 135km north of Alice Springs.
Arafura will mine for neodymium and praseodymium, with a goal of supplying 4440 tonnes per annum, estimated at five to 10 per cent of global demand.
EY spokesman Luke Branson said the US-Australia investment was very welcome given the sector had "struggled to gain traction due to volatile markets and high startup and ongoing costs".
