A Top End pastoralist is urging the Federal Government to confirm whether or not it will build a nuclear waste dump on land in the middle of his property so he can plan for the future.

Barry Utley's property, 40 kilometres south of Katherine, surrounds one of four Northern Territory defence sites nominated by the previous Federal Government to be tested as a location for a nuclear waste repository.

Mr Utley, who is on the property by himself, has written to the Federal Government but the replies have given him no certainty about his future.

"I was looking at selling land further up [that] we don't use and also this other block ... I can't see that anybody will want to buy a block of land with this hanging over their head."

Northern Territory Labor Senator Trish Crossin says the Government can not do anything until assessments are finalised on the four Territory sites.

Senator Crossin says the report was due mid year, but the exact timing is unclear.

"My understanding is that Minister Ferguson is still waiting for the final report to come in from Parsons Brinckerhoff, the company that was actually contracted to examine the sites for their suitability, and once the report has been handed to the minister and he's had time to look at it, he will take the next step."