MELBOURNE, Nov 19 (Reuters) - Australia's minerals agency has...

MELBOURNE, Nov 19 (Reuters) - Australia's minerals agency has signed a deal with its United States counterpart to jointly develop a better understanding of both countries' critical minerals reserves, Australia said on Tuesday.

GeoScience Australia and the United States Geological Survey (USGS) signed the agreement, which did not mention any specific funding, that will also look at better quantifying the global supply potential of critical minerals such as rare earths, Australia's Resources Minister said in a statement.

Critical minerals are a suite of elements such as lithium, cobalt and neodymium used in high tech technologies like renewable energy, electric vehicle batteries, and defence.

U.S. and European governments are trying to broaden the supply chain of critical minerals including rare earths, which China dominates. But developers say the governments are too slow to make funds available.

“The U.S. has a need for critical minerals and Australia’s abundant supplies makes us a reliable and secure international supplier of a wide range of those, including rare earth elements," Australia's Minister for Resources Matt Canavan said.

The announcement comes as Australia's Prime Minister Scott Morrison visits the United States this week, and builds on an initial agreement signed a year ago. Australian rare earths developer Northern Minerals (NTU) will be part of the country's delegation to Washington, it said in a stock exchange filing on Tuesday.

The research agreement will focus on mapping potential critical mineral resources and prioritise developing big data to understand supply and demand scenarios for developing the critical minerals pipeline, the statement said.

The announcement did not mention funding for specific mining projects.

There are expectations that the United States may finance some critical mineral projects after President Donald Trump in July authorised U.S. Department of Defense funding to be directed to resources or technology "essential to the national defense" to shore up domestic supplies.

Rare earths are highly prized because of their strong magnetic properties, crucial to industrial magnets used in some types of missiles, but the extraction process is highly complex and expensive to set up.

Australia's Lynas (LYC) , the world's biggest rare earths producer outside of China, signed a preliminary deal in May to build a heavy rare earths processing plant in Texas.

No final decision has been made on that plant and Lynas has also signed an initial deal to build a new rare earths processing plant near its existing facility in Malaysia.