A URANIUM mine in Kakadu National Park has been given the green light to explore a new ore deposit without the need for environmental assessment.

The Territory Government yesterday gave Energy Resources Australia the approval for further exploration of the Ranger uranium mine in Kakadu National Park.

The company wants to build a 3km long tunnel up to 450m underground.

The mine will need Commonwealth and Territory approval if it is to go ahead.

Federal Environment Minister Peter Garrett said that yesterday's decision was only an "exploration approval".

"There is no formal application to mine," he said.

"Nothing has reached me. I have no proposal in front of me.

"Until such time as I have the proposal in front of me, I don't have any further comment."

But Mr Garrett - a former anti-nuclear campaigner - did not rule out approving more uranium mines.

"Any proposal that comes before the government would be considered in the same way that this proposal was - thoroughly, diligently, with a very strong focus on maintaining world's best practice in terms of proposals of this kind," he said.

"I will continue to make sure that the environmental standards are as high as they need to be.

"And I'll take any proposals that come through to us and treat them in that manner."

The NT Department of Natural Resources, Environment, the Arts and Sport issued a statement last night saying the Minister determined that ERA's proposal did not require environmental assessment.

"The proposal by ERA is principally for an exploratory activity to evaluate the viability of underground mining," it said.

"As a result, it was determined that the exploratory activity would be unlikely to have significant environmental impacts."