US says it will help develop Kenya's critical minerals processing

U.S. company Critical Metals Corp and Australia's RareX said in July they had been shortlisted to compete for the rights to develop Mrima Hill. Kenya's government has not published a shortlist.

Ruto told Reuters in June that Kenya and the U.S. were close to sealing a critical minerals deal. Neither side provided an update on the agreement on Wednesday.

Garcia said the United States favoured a mining development model that includes local processing and value addition in producing countries.

"Some of our competitors are efficient at one thing: pulling minerals out of the ground, whisking them offshore and capturing all value addition far away from the lands from which the minerals originated," he said.

China, which has faced criticism from some governments and advocacy groups over exporting raw minerals for processing elsewhere, has rejected such accusations.