Rio Tinto still has the lithium bug, on top of its ambitions for copper, iron ore, bauxite, aluminium and alumina and the obscure mineral scandium which it produces in Quebec and possibly soon in Australia.

Rio's Australian annual meeting in Perth on Thursday heard from CEO Jakob Stausholm who revealed that, while his company remains very interested in lithium, it didn't want to pay too much to play.

But chair, Dom Barton also told the meeting that the company is under growing pressure from parts of the US government and industry to get its massive Resolution copper mine up and running.

The project has been blocked for years by activist opposition on environmental and native rights.

"We are getting immense pressure to proceed because of the copper reserves that are there," Barton told shareholders at Rio Tinto's Australian shareholders meeting.

Pressure was coming from "parts of the U.S. government," Barton clarified on a media call following the meeting, as U.S. senators seek to get copper put on the U.S. critical mineral list which would allow copper projects access to tax breaks.

"We are engaging and we are not (making) any conclusions but we are going through a process right now," CEO Jakob Stausholm said.

But lithium is a headliner grabber and Rio has had something of a chequered career so far in key battery metal.

Its $US2.5 billion plan for a major mine and refinery in Serbia is on the back burner after strong opposition and it is reviewing the start-up costs for its Rincon project in Argentinia because of the country's surging inflation (over 100% a year), weakening growth and a sinking currency.

"Of course, I don't like any cost overruns but, on the other hand, it basically provides invaluable learnings for us before a project is being recommended for full sanctioning," Stausholm said.

Rio paid $US825 million for the Rincon prospect and said it would spend $US140 million on development work on Rincon but that is being reviewed because of the explosion in costs.

Stausholm told media after the AGM that "We wouldn't mind having a stronger lithium business."

"I think it is very difficult to justify to go in and buy at these high prices unless you already know you can sell the lithium at a high price," which is uncertain, he said of the potential for dealmaking.

Lithium prices have slumped sharply since peaking last November. Albemarle has downgraded its outlook, but another US producer, Livent has upgraded its 2023 outlook despite the weak prices.

Stausholm said the outlook for long-run lithium prices is unclear.

"I'm not sure the short term is giving you any indications of" long-term pricing, he said. "What we do know is the world needs to build a number of lithium mines."

Mr. Stausholm said he remains hopeful of a way forward for Rio Tinto's lithium project in Serbia, which came to a halt last year when the government there revoked its licenses.

His caution is in contrast to the spending by Albemarle - there's the $US1 billion on two new hydroxide refinery processing trains in WA and the proposed $US3.7 billion bid for Liontown Resources while Wesfarmers and SQM of Chile are looking at spending more money expanding their mount holland mine and associated WA refinery.

The slide in Chinese prices has seen the share prices of local producers fall, but all are pressing ahead and not as seemingly hesitant as Rio is here.

Rio shares rose 1.2% to $110.14 at the close on Thursday.