SYDNEY (Reuters) -The United States and Australia have extended financial support to several Australian companies as part of a wide-ranging critical minerals agreement signed on Monday with an aim of countering China's hold over the industry.

Under the agreement signed by U.S. President Donald Trump and Australian Prime Minister Anthony Albanese, the two countries pledged to invest at least $1 billion each over the next six months in mining and processing projects and to set a price floor for critical minerals, a step long sought by Western miners.

The governments would also help advance a plan by U.S. aluminum producer Alcoa ( AA ) to build a gallium plant alongside its alumina refinery in Western Australia, the company announced in a statement.

Alcoa ( AA ) in August signed a joint development agreement with Japan Australia Gallium Associates (JAGA), a venture between the Japanese government and Sojitz Corp, for the project.

It said on Monday that once it finishes feasibility work, a special purpose vehicle owned by the U.S. and Australian governments and Alcoa ( AA ) is expected to enter a joint venture with JAGA to construct the plant, which Alcoa ( AA ) would operate.

The parties would provide capital to the special purpose vehicle and receive gallium offtake in proportion to their interests. The plant would be expected to produce 100 metric tons of gallium annually, Alcoa ( AA ) said.

Gallium, a raw material used in the production of alumina, is a critical mineral essential to technology, especially the semiconductor industry and defense sectors.

Reg Spencer, mining analyst at Canaccord, said the move was a positive development that could boost the prospects of Australia-listed companies.

Meanwhile, the Export-Import Bank of the United States (EXIM) announced it sent seven Letters of Interest (LOIs) totaling more than $2.2 billion to advance U.S.-aligned critical minerals projects in Australia.

The LOIs were issued to Arafura Rare Earths ( ARAFF ), Northern Minerals ( NOURF ), Graphinex, Latrobe Magnesium ( LTRBF ), VHM, RZ Resources and Sunrise Energy Metals ( SREMF ). They represent the next phase in securing the minerals that power American manufacturing, national security, and other strategic industries.