The pair have signed a heads of agreement to discuss potential collaboration in mineral exploration, both inside and outside China.
Minmetals chairman He Wenbo said the partnership would help "secure mutual global opportunities for quality resources" and enhance the company's long-term development in the mining sector.
Rio CEO J-S Jacques said Minmetals was rapidly becoming an important player in the global mining industry and the partnership put them in "the best possible position".
"Our complementary strengths in exploration across the globe put us in the best possible position to find the metals and minerals that are essential to our modern lives," Jacques said.
Partnerships can maximise exploration budgets that were cut after the 2015-2016 commodity price crash, Reuters noted, adding flexible arrangements could increase the range of commodities miners were exposed to.
Rio's recent announcement to spend US$23 million on a feasibility study for the Koodaideri iron ore mine in Western Australia stressed the project would replace, not grow, existing production.
The duo will formalise the agreements and set up joint teams to identify potential exploration targets.
The agreement follows a memorandum of understanding between the two companies in March committing to examine opportunities for cooperation and collaboration.