Federal Environment Minister Peter Garrett says he would like to seize the opportunity to expand Kakadu National Park, following a request from traditional owners.

The French mining company Areva wants to mine the Koongarra deposit for uranium.

The site is surrounded by Kakadu National Park and home to the Djok Aboriginal clan.

For years, traditional owners have rejected the company's requests to mine the site, but now they are taking their fight even further.

On behalf of Aboriginal land owners, the Northern Land Council has submitted an application for the site to be included in the national park.

In a statement, Mr Garrett says including land adjacent to the park is a once in a generation opportunity he is keen to see realised.

He says there are important questions of Indigenous rights and natural justice that need to be worked through, and those processes will continue to run their course.

The site is believed to hold about $5 billion worth of uranium.

The Australian Conservation Foundation is urging the Federal Government to move quickly.

Foundation spokesman Dave Sweeney says traditional owners should be commended for putting the environment before money.

"The opportunity is there, the time is there, the need is there and the capacity is there, for the Federal Government to act really positively, really promptly, and deliver a fantastic and important bit of country into the permanent protection of Australia's largest national park," he said.

"The Federal Government needs to chose which is more important - the long-term national interest of Australia or the corporate interest of a French nuclear company."