The uranium mining company, Energy Resources of Australia (ERA), has apologised to traditional owners for failing to report high uranium levels found within Kakadu National Park in January.

The Mirrar traditional owners of the Ranger and Jabiluka uranium leases says elevated uranium levels were found at four checkpoints within the park but ERA failed to report them immediately.

The company's Bob Cleary says regulatory expectations were met but the company fell short of meeting the expectations of stakeholders.

"I have to apologise to the traditional owners for that and assure them that I am making sure that we are setting up a communications system so that every employee in the company understands that commitment we've made and doesn't leave it to someone else to make that communication," Mr Cleary said.