The Australian Conservation Foundation (ACF) has urged Rio Tinto to stop a planned expansion of the Ranger uranium mine in the Northern Territory.

Rio Tinto subsidiary Energy Resources of Australia (ERA) runs the uranium mine on a lease inside Kakadu National Park.

Production is currently suspended following a record wet season in the Territory and Rio Tinto is holding its annual general meeting in Perth today.

ACF spokesman Dave Sweeney says it should use the opportunity to scale back plans for the mine.

"Ranger is a leaking, ageing and under-performing mine," he said.

"The mine is currently shut. It is not turning a dollar.

"It is losing contaminants into the environment and it is losing money for Rio Tinto and ERA."

Mr Sweeney says Rio Tinto should do more to ensure Kakadu is not affected by the mining operation.

"It is in their interests... to show that they are genuine about their rhetoric of best practise," he said.