MELBOURNE/TOKYO (Reuters) - Australia's resources minister has begun a week-long trip to South Korea and Japan to discuss gas exports and critical minerals opportunities, as its government on Monday released a "prospectus" of 52 investment-ready critical minerals projects.

The resources-rich nation is seeking investment from allies in projects to develop minerals critical to green energy and is at risk of supply chain disruption, spanning rare earth processing to various cobalt and nickel-producing mines and plants.

"Australia's critical minerals are key to the world's energy transformation," said Minister Madeleine King in a statement.

"But we need to attract investment to get these minerals out of the ground, to process them here, to build the batteries, wind turbines and solar panels required to make the switch to a lower carbon economy," she said.

King will be meeting Japan's trade minister Ken Saito, and South Korean trade and energy minister Duk-geun Ahn, she said in a statement.

The minister is also expected to engage her counterparts on natural gas as Australia develops its future gas policy, given both nations are large customers of the major exporter.

"As Australians ... we can't ignore the role we need to play in providing for the energy security of large economies like Japan, and also others like (South) Korea and China as well as Singapore ... the Philippines as well as Malaysia," King told reporters in Tokyo.

The push for investment comes amid a global downturn in prices for electric vehicle battery materials lithium and nickel, which have been hit by slower-than-expected electric vehicle uptake. For nickel, a flood of Indonesian supply has also hit prices.

Already this year, a string of Australian nickel projects have been iced, including part of BHP's (BHP.AX) operations in the state of Western Australia. More are expected as miners report production this week.

King spent last week meeting industry leaders at several round tables in the country's resources heartland of Western Australia state amid announcements of closures and job cuts.

She pledged support for the sector and said she was determined to ensure Australian miners could compete with cheaper but lower-grade minerals produced in less environmentally friendly ways overseas.

"Australia has the potential to become a long-term reliable supplier to Japan of critical minerals and rare earths. Just as Japan helped build Australia's iron ore and LNG industries, Japan can help Australia's critical minerals and rare earths industries," King said in Tokyo.