An excavator at a mine in the Kirovohrad region, Ukraine. The US is in talks to set up a $5 billion fund to invest in mining, in what would be the government’s most significant foray into dealmaking to boost supplies of critical minerals. The US International Development Finance Corp. is in discussions to establish the fund as a joint venture with New York-based investment firm Orion Resource Partners, according to people familiar with the matter, who asked not to be identified because the talks are priva ...